The search is feeble for me, so I will ask the question: Driving through some inclement weather here near Pittsburgh, I selected the defroster button to defog my windshield. After it was clear, I pushed the button again, but it did not unlatch, remaining stuck in the defroster position. The button action feels normal, but doesn't always come back out. After futzing with it, it finally unlatched after I pressed it in one last time. Does anyone have insight on preventative maintenance or known issues with these? I have owned 4 Volvo 240's over the years and have never had one do this.

Thanks in advance for any tips!