I use ProtonVPN. It wasn't until Spotify stopped working sometime later (403 Forbidden for all HTTP requests) that I narrowed it down to using VPN.
Seems to be a growing thing. Thankfully, Spotify didn't do anything to my account, and it continued to work from regular IPs.
I also used a tunnel when Spotify was not available globally. It did not create any issues.
Using a Public VPN is double edged sword. If you really need it its better to setup a wireguard tunnel to a own server as the the Public VPN IPs as monitored by the security companies and also get abused all the time.
the developers are now working on adding captcha at the application level and also signing the api endpoints.
You can.
I know because our information security office did it to all of our web endpoints. Which are mostly API endpoints. Without telling anyone involved with individual apps, before or even, until specific complaints got to them, after doing it.
I feel your pain. It's stuff like that that just makes you know, they not only have no idea what they're doing, the level of agency and access they have mean it's just a question of when they finally accidentally something big on fire one day - and whether you'll be able to make it out unscathed with eg just some lost sleep.
Would probably make a good story for http://old.reddit.com/r/talesfromtechsupport, as you're probably already aware. If you feel like (and can stand) writing it (heh).