I have first noticed it yesterday, not sure if it was broken already before: When normally using the New Wikitext Editor, as I have done for several years, it seems to be impossible now to insert any templates or references. When I use the dialogue for adding a reference and press the blue button to insert it, it loads but nothing is inserted into the page (the save button does not turn blue, so there is no edit made at all); same with trying to insert any template via the template dialogue. Tried it multiple times, no edits are made. At the same time, in Visual Editor everything works just fine. When I copy a reference from a page in Visual Editor and try to insert it properly in my NWE edit window, even that fails. This is incredibly annoying, I cannot work properly anymore.
I use Chromium on Win10 and have tried this in German and Italian WP. No errors in the browser console.