Update: same thing if typing - (minus sign) then using intellisense. It doesn't do it with a + (plus sign) or some other operators though. With the plus sign, intellisense pops up not after I type + or space, but after I type the first letter of the next word. But the equal sign and minus sign pop up intellisense immediately. Maybe this is only an issue with operators that immediately launch intellisense (as opposed to typing another word or value).

@jrieken This looks like a bug in code assist:

<script>
const abc = 5;
const def =

• code assist after = brings up a list of proposals
• entering a space does not filter any proposals, all seem to be still valid, no new request is made against to Language server
• applying the proposal will insert it without space.

I checked that this issue is also present in 1.13.1.

Hm, that came in when fixing #26096 which was about ignore whitespace in some cases...

Also a little unhappy because when having requested intellisense explicit via Ctrl+Space we don't hide the box when nothing matches anymore. So, even after fixing the filtering you will see the exact same behaviour. This issue is actually half as-designed and half a bug. Not sure what to do

I have pushed changes to cancel intellisense when non-word characters are being typed when otherwise go to the frozen state. That fixes this issue, the IntelliSense window closes after typing space.