I ran into this recently with a new PP account I setup. Everything was fine & suddenly a random "please verify" question comes up. After passing it, the account is in limited status and the options to verify it AGAIN I found irritating.
Here's how you handle it.
You begin by keeping your attitude & frustration in check, because nothing will benefit you by being crappy, and PayPal cannot even explain the security model so it's frustrating for them too. Call and explain that you suddenly noticed that limitations are on it, and your not sure what made your account change, because it was in good status the last time you were able to view it. Then comment that maybe you should have made it a business account vs personal, because you accurately provided the required information at the time you registered, and since then have made transactions with no problem, but suddenly there's a problem and that concerns you. Wait 3 seconds, and nicely ask if you have done something wrong, because you recently assisted your father in setting up a verified account and he's had a good experience, so what has went wrong???
Most likely by now the agent has offered to look into it to see what they can do, and this is when you thank them for their time & consideration.
Most likely they will return with a generic reason that references security/protection etc and the limitations have been lifted leaving the account in good status.
Remember this: If you travel, use a VPN or anything that shows variance in the IP address, THAT is what likely initiated an alert that moves the account into limited status.
If you do use VPN or move around you are best served by mentioning it to them instead of them watching your account like a cat & a mouse. If you take the few minutes to handle this concern fully, it will keep you off the radar in the future.
What most people don't get about PayPal is this. They deal with a tremendous amount of issues, and in recent years they have made effort to balance their algorithmic security with humans that can make decisions & resolve problems. So if you handle it politely, and demonstrate that your reasonable they are most likely going to "like" to help you get it right.
Good Luck