Does anybody happen to know an expert on patio door shutters

Good morning. We have a problem with one of our patio door shutters, ie it doesn´t work!! It would seem that the fault actually is because of a defective Remote. Occasionally it will operate the shutter but 90% of the time it refuses. I have fitted a new battery but that has not helped. Alas, the remote has no identification on it so unable to contact maker.
Any help would be very much appreciated. Many thanks. Adrian

Have you looked behind the battery ?

Yes, also had a very good local DIY tradesman look at it but without success.