@Catweazle Ok, but which specific version? When testing something, please say the specific version you used; saying "the last stable" is not very useful.
In any case, when you tested this, did the address field look like it does on the left image (Best Result (...)), or the right image (Go To) below?
Screenshot 2024-03-19 at 13.34.29.png
Screenshot 2024-03-19 at 13.34.37.png
The left side will work and go the the specified URL because you already visited it before and what you typed is being matched to a history item, while the latter will always fail, regardless of the used search engine.
Alternatively, did you try with a fresh profile? Testing with a fresh profile is the best way to narrow down the source of the issue.
I was also able to reproduce using Aria as the default search engine on a fresh profile with stable version 6.6.3271.50:
Screen Recording 2024-03-19 at 13.42.27.gif
Notwithstanding, as I mentioned earlier, the issue is already fixed on snapshot 3291.3.