@Max_Saravia
The calendar fails to calculate the size properly as the tab is hidden initially.
We have an Update Size event available for the calendar which will fix this, but the Bootstrap 4 tabs don’t have dynamic events which you can directly use in the UI.
You can use the built in Bootstrap 4 events for the tabs as follows:
<script>
$('a#navTabs1_2_tab').on('shown.bs.tab', function (e) {
dmx.parse('calendar1.updateSize()');
})
</script>
Just replace #navTabs1_2_tab
with the ID of your second tab button and calendar1
with your calendar ID, and put this script block at the bottom of your page.