I will update the save that it doesn’t format PHP pages. The formatter from monaco is for HTML and seems to have some problems with the embedded PHP code. For now it is best to disable the formatting until we find a better formatter which will support PHP code.
Will this just be for format on save (rather than formatting manually)? I don't use the 'on save' option but I use the formatter frequently and it seems to work very well, at least with v3.9.9.