5 amps is quite a low current rating for the fuse. I would tempted to try a 7.5 or 10 amp fuse assuming the intermittent fuse blowing isn't a fault as such, just the load on the motor. I would also check that window movement is not impeded.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone