PM, unwanted name change when posting reply

I'm hoping someone can help me please.

One of my admin is having a recurring problem in that every time he tries to send a reply to a pm by clicking 'post reply' he ends up with his own username in the send to box when it should be for instance, my name if he were replying to me. He created a second account to test the problem and it was exactly the same for the non admin test account.

It's working ok for me, but i can't understand why he keeps having the same problem. He can't be doing anything wrong because there's only 1 option to post reply.

Does anyone have any ideas please. it's driving him a bit mental now.

Thanks in advance

This is kinda weird problem, but maybe clearing cache can help? Try instructing him to clear his cache https://help.forumotion.com/frequently-asked-questions-f5/how-to-clear-the-cache-in-ff-ie-t22597.htm

Thanks for your suggestion. He has tried but unfortunately he's still getting the same problem.

After he clicks reply and it's already chosen his own name, he can change the name to whoever he wants to send the pm to, but by the time he's finished typing, it's reverted back to his own name.

Very frustrating as he's admin and sends quite a few pm's out, and has had loads go to himself