No issues here. Try disabling your cookie manager extensions completely to see whether they are causing you the trouble at all. There might be something else doing this. You seem to be very privacy-minded; are you using VPN by any chance?
Naah, I'm not going to disable cookie manager/cleaners just because one site can't authenticate users properly - I'll simply just switch to another site/pool.
No VPN at the moment.
Well, don't blame the pool for what you are experiencing when no one else is having this issue. The problem relies in your machine clearly. What difference does it make adding an exception or turning the extension off completely when using MPH? Especially for testing...
As I said before, recaptcha is not the way to secure logins (which is why MPH introduced it) - solving it can be automated with few cents a piece so it's just selling an illusion to the users that things are secure. That is my critique. Having to log in once or twice a day is not an issue, being coerced to get tracked by and work for Google's benefit for good 15-30 seconds is. If this is ok with you, that's all cool, not giving a shit and being blind is what made Google so big but don't tell me that I should be ok with this.
You don't have to be offensive to prove a point especially when people are trying to help. You can just go with one of your initial suggestions and use another pool and I just end the conversation here.