Alarm Base Station keeps loosing connection in middle of the night !!!

I have an alarm base station - connected to wifi, also have a retrofit kit. all has worked fine for years. now, every night, around 1am, 2am or 3am, my alarm is loosing connection, running on cellular backup, for around 1 or 2 minutes, then re connecting to wifi.. it is doing this almost every nigh, some times a few times. it also does it in the middle of the day sometimes.. its starting to drive me crazy... any idea why it would keep dropping????? what would cause it to do this???