I took out all the relations to tagify as suggested, and added a new tagify component which readded 4 lines to the bottom of the head.
I just sent a portion of my head scripts, but here is the full one as I know I added my own calendar scripts as per the full calendar site in order to support the view i wanted to use.
<head>
<base href="/">
<script src="/dmxAppConnect/dmxAppConnect.js"></script>
<meta charset="UTF-8">
<title>Untitled Document</title>
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.14.0/css/all.css" integrity="sha384-HzLeBuhoNPvSl5KYnjx0BT+WB0QEEqLprO+NBkkk5gbc67FTaL7XIGa2w1L0Xbgc" crossorigin="anonymous" />
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="bootstrap/5/css/bootstrap.min.css" />
<link rel="stylesheet" href="css/style.css" />
<script src="https://code.jquery.com/jquery-3.5.1.min.js" integrity="sha384-ZvpUoO/+PpLXR1lu4jmpXWu80pZlYUAfxl5NsBMWOEPSjUn/6Z/hRTt8+pR6L4N2" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js" integrity="sha256-VrmtNHAdGzjNsUNtWYG55xxE9xDTz4gF63x/prKXKH0=" crossorigin="anonymous"></script>
<script src="/dmxAppConnect/dmxRouting/dmxRouting.js" defer=""></script>
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/core@4.4.2/main.min.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/core@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/daygrid@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/timegrid@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/timeline@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/resource-timeline@4.4.2/main.css" />
<script src="https://unpkg.com/@fullcalendar/core@4.4.2/main.min.js" defer></script>
<script src="https://unpkg.com/@fullcalendar/core@4.4.2/locales-all.min.js" defer></script>
<script src="https://unpkg.com/@fullcalendar/interaction@4.4.2/main.min.js" defer></script>
<script src="https://unpkg.com/@fullcalendar/daygrid@4.4.2/main.min.js" defer></script>
<script src="https://unpkg.com/@fullcalendar/timegrid@4.4.2/main.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/timeline@4.4.2/main.js"></script>
<script src="https://unpkg.com/@fullcalendar/resource-common@4.4.2/main.js"></script>
<script src="https://unpkg.com/@fullcalendar/resource-timeline@4.4.2/main.js"></script>
<script src="/dmxAppConnect/dmxCalendar/dmxCalendar.js" defer=""></script>
<script src="/dmxAppConnect/dmxFormatter/dmxFormatter.js" defer=""></script>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyAvrBLAHBLAHBLAHQ1VWNPA&libraries=places"></script>
<script src="/dmxAppConnect/dmxGooglePlaces/dmxGooglePlaces.js" defer=""></script>
<script src="/dmxAppConnect/dmxGoogleMaps/dmxGoogleMaps.js" defer=""></script>
<script src="/dmxAppConnect/dmxGoogleMaps/themes/silver.js"></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxValidator/dmxValidator.css" />
<script src="/dmxAppConnect/dmxValidator/dmxValidator.js" defer=""></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxBootstrap5TableGenerator/dmxBootstrap5TableGenerator.css" />
<link rel="stylesheet" href="/dmxAppConnect/dmxDatePicker/daterangepicker.min.css" />
<script src="/dmxAppConnect/dmxDatePicker/daterangepicker.min.js" defer=""></script>
<link rel="stylesheet" href="/dmxAppConnect/dmxDatePicker/dmxDatePicker.css" />
<script src="/dmxAppConnect/dmxDatePicker/dmxDatePicker.js" defer=""></script>
<link rel="stylesheet" href="css/bootstrap-icons.css" />
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Work+Sans:wght@100;200;300;400;500;600;700;800;900&display=swap" rel="stylesheet">
<script src="/dmxAppConnect/dmxBootstrap5Navigation/dmxBootstrap5Navigation.js" defer=""></script>
<script src="/dmxAppConnect/dmxBrowser/dmxBrowser.js" defer=""></script>
<script src="/dmxAppConnect/dmxBootstrap5Toasts/dmxBootstrap5Toasts.js" defer=""></script>
<script src="/dmxAppConnect/dmxBootstrap5Modal/dmxBootstrap5Modal.js" defer=""></script>
<script src="/dmxAppConnect/dmxBootstrap5Popovers/dmxBootstrap5Popovers.js" defer=""></script>
<script src="/dmxAppConnect/dmxGeolocation/dmxGeolocation.js" defer=""></script>
<script src="/dmxAppConnect/dmxBootstrap5Collapse/dmxBootstrap5Collapse.js" defer=""></script>
<script src="https://unpkg.com/@fullcalendar/google-calendar@4.4.2/main.min.js" defer></script>
<script src="https://unpkg.com/@yaireo/tagify" defer></script>
<link rel="stylesheet" href="https://unpkg.com/@yaireo/tagify/dist/tagify.css" />
<script src="/dmxAppConnect/dmxTagify/dmxTagify.js" defer></script>
<link rel="stylesheet" href="https://unpkg.com/@yaireo/tagify" defer />
</head>
And here is the calendar part itself
<dmx-datetime id="var_today_now" interval="minutes" utc="true"></dmx-datetime>
<dmx-value id="var_today_now_adjusted" dmx-bind:value="var_today_now.datetime.addHours(2)"></dmx-value>
<div class="mt-5">
Schedule/Calendar
<dmx-calendar id="availability_calendar" views="dayGridMonth,timeGridWeek,timeGridDay" view="timeGridWeek" dmx-bind:now-indicator="var_today_now_adjusted.value" locale="en-gb" dmx-on:eventclick="sc_fetch_single_availability.load({which_event: $event.event.id})" dmx-on:eventresize="sc_resize_event.load({event_to_resize: $event.event.start+$event.event.end+$event.event.id})">
<dmx-calendar-source id="source_db" dmx-bind:events="sc_fetch_db_availability.data.query_availability" event-id="id_av" event-title="av_product_code" event-start="av_start_time" event-end="av_end_time" event-all-day="av_all_day" event-color="av_start_time < var_today_now.datetime ? cl_colour.replace('rgb','rgba').replace(')',',0.4)') : cl_colour" event-editable="pis_is_master" bs4-tooltip="" bs4-tooltip-title="event.extendedProps.av_seats_available+' Seats Available on '+event.extendedProps.pis_product_original_name+' – '+event.extendedProps.pis_external_product_identifier"></dmx-calendar-source>
</dmx-calendar>
</div>