I had a similar experience with Google's support this year when I logged to my older Google account from a new device, and I was automatically logged out from everywhere, when I was trying to login again it asked me to provide an OTP, when I asked the form to send me the OTP, it said that I've done so many attempts.

Later, I learnt that this is actually very common problem, if you see the "Me too" count on the Google Community Help, it's about 20K (https://support.google.com/accounts/thread/52598991/my-gmail...) users, that's a huge amount of false positives that Google refuses to care enough about to make a change in their automated account process, which they keep bringing up when users complain, they say the process is automated and nothing could be done about it (well, you are a tech company, can't you like change the code or something?). Unironically I had to wait uncertainly for a week then try, which did not work (same too many attempts), then after two weeks, then after couple of months, until I just gave up and created a new account. After 4 months I was able to finally login again.