No bank will touch you with a ten foot pole if you are even remotely associated with the US.

Yep, and I find it so very American to leave that tid bit out of their complaint and then it getting upvoted because muh evil EU? when its really the US goverment screwing their abroad citizens in this case.

Why? What are the issues involved?

FATCA reporting.

Roughly speaking Congress was worried about Americans hiding money abroad to avoid taxes so they passed extremely punitive laws. This ended up being mostly pointless because the real tax evasion is done by people who pay lawyers and lovbyists to make sure it's all legal.

If a foreign financial institution has a US depositor they have to fill out a ton of IRS paperwork. If they mess it up the IRS can impose an extra 30% tax on all the institution's US income.

I’m a U.S. citizen and currently have bank accounts in 3 EU countries and one other non-US country.

The bank I expect will kick me out doesn’t want non-EU citizens who are not EU residents. The bank that did, I think it was because of my citizenship (I was a German permanent resident at the time) but I’ll never really know as they didn’t give a reason, just 60 days notice.

Banks will deal with you, but not all banks, and some banking products (like brokerage accounts) are off limits.

Did you file a complaint with the local banking regulator? You should do that in the future.