What were you doing?

Fresh installation, URL adjusted.

What did you expect to happen?

Chromium does not display the "Translate" bubble

What happened instead?

Chromium shows the "Translate" bubble, Similar to this:

Version of FullPageOS?

2021-03-04-fullpageos-no-acceleration-buster-armhf-lite-0.12.0

Solution

The chromium command line flag to disable the translate-bubble was renamed from "TranslateUI" to "Translate":
see commit

Must be adjusted in the scripts/start_chromium_browser file
from --disable-features=TranslateUI to --disable-features=Translate