This seems like some new problem with VE. Tested in Firefox 86 (current).

Steps:

1. Polish Wikipedia, any article.
2. Type "{{" (template).
3. "Snookerzysta infobox".
4. Fill first field/parameter.
5. Add and ignore warnings.
6. View changes (don't save please ;-))

Result

Only a filled parameter is present in code. So only one is visible in code preview. Both required parameters and suggested ones are removed by VE (not by user).

Note that the same thing happens on enwiki. Was just easier for me to find a good example on plwiki. On enwiki you can test e.g. with a "Infobox station" template and fill just an "address" field (you will notice that "name" is not present in code).

Expected

All parameters that are not removed in VE must be present in code. This includes both required and suggested parameters.
Required parameters must remain unremovable in VE (as they are now).

https://pl.wikipedia.org/w/index.php?title=Wikipedia:Kawiarenka/Kwestie_techniczne&oldid=63164814#Wstawianie_szablon%C3%B3w_w_edytorze_wizualnym