Thank you for the information!

Log into the site from your browser on the same computer/network before logging into the app

For some reason that didn’t work for me. I tried to log in from the very same computer/OS from Firefox browser all the time (I believe even the browser tab was open, though maybe wasn’t refreshed for some time) - and was badly blocked by a wall of captchas.

That said I get captchas on “regular” web sites from time to time from this specific network, that may mean that my internet provider may be considered not trustworthy by some services. But those are always a couple of captchas, not over a dozen.