No. That only happens if I have to clear the cache on my iPhone, which happens like twice a year. I have a 7Plus which is driving me crazy lately, but I don’t like 12 & 13 either so I’m gonna wait a bit longer for a new one. Sigh.
I have a 5 yr old iPad. I keep the software up to date (not implying that you don’t). If I reboot, or turn it off and on, I have to re-login. The same on my iPhone 11 Pro. If I accidentally close the tab that FR is open in and reopen FR, I’m still logged in.