Remote development issues (tabbing and emmet)

Hi there, I've been using Remote development with SSH for a few weeks now and I love it, but I'm having issues where some autocompletions like github copilot or variables in php don't work. So it shows up, but when pressing the Tab key to autocomplete, it seems like a works for half a second but deletes itself.

The most problematic for me though is that emmet doesn't work :( So if I write “div.testing-class” and hit Tab, it behaves like a standard tabulation. That means that I have to manually write my html, which is a bummer.

Any ideas of what could be the issue?