Yes, this happens. Some companies blindly block any IP that's part of the Tor network even if they're just relays. Apple Discussions used to do this, I don't know if they still do.
I consider it a good filter for companies I don't want to do business with.
my old company had some bad stuff come out of tor nodes, hired a company to do some analysis, they found i ran a relay at home (employee vpns to work from home from a tor node, is what they said) and thought it was suspicious. so i was called to security and given the grief. sometimes its not worth running a relay from home...
You're not paranoid, many providers do this despite the fact that running a relay doesn't generate any malicious traffic. Here's a similar experience from Filippo Valsorda: https://twitter.com/FiloSottile/status/1257714275763851264
A friend of mine wound up unable to pay their TV bill after spinning up a Tor relay - the connection to the site would just time out.
Said friend worked at said TV company and pulled some strings inside to get it investigated. Turns out, by default, a number of IPS systems deny traffic from relays for no good reason. He was unsuccessful in getting the security people to turn that bogus rule off.
The network never promoted my node to an entry but it operated as a relay.
One thing I noticed that my IP must have suddenly been in some lists. I can't prove it but on multiple forums my IP was blacklisted an I had issues accessing some services from telco providers. Never had these issues before and never again after I stopped running the relay... maybe I'm just paranoid.