the loan fails

Hello everyone, I wanted to see if you can help me with the problem I have, you will see I share my library with my friend, he only uses the garrys mod, everything is fine, the problem is that the next day the game crashes and the option to ask appears Borrowed, the problem is that when sending the steam request it throws an error that says that I, the owner, have to access his account again, obviously I did it and he left him again, but the other day the same thing happened again infinitely and the I'm really tired of going in and out every day and any solution or reason why that happens?