The signals are analog so it's a problem with the phone line?
It establishes a connection with the password but when I hit the apply button, the password length increases in its field by itself.
Ohh...
From the much I can say about this, since modems are analog devices if your phone line signals are problematic, then that might be what keeps on causing it to reset. Is your phone line working fine? If this is a problem you are only experiencing tonight, it's nothing to worry about as it could just be a random signal problem. If it continues and there is no problem with your phone line, then get your modem checked. But I feel like it's a temporary problem and will be fine tmrw.