This is usually due to your hosting provider utilizing server-side caching. You should ask them to exclude TML’s paths from the cache, which by default are:
/login
/logout
/register
/lostpassword
/resetpass
/dashboard
/profile (If using Profiles extension)
/activate (If using Moderation extension)
/2fa (If using 2FA extension)
I’ve had the same issue. I’ve already cached these pages. This wasn’t an issue previously, but suddenly has been for the last couple of months, so it seems related to an update. I’ve also contact support multiple times to let you know this recommended solution does not work, but still haven’t heard back.