Alarm switched off via keypad. Alarm goes off anyway

As can be seen in the pictures, I turn up, open the door, enter pin in keypad, phone tells me alarm is deactivated, I proceed through to the office and the alarm goes off. I then deactivate it again via my phone.

Even though it worked this time, the front door sensor keeps dropping from the system, I then have to reboot the Homebase to get it to connect again. I’ve changed the battery even though it tells me it’s ok. Distance can’t be a problem as this workshop is smaller than my house.

Everything on the system works fine, yet it keeps telling me I have to bypass something. So I deleted everything, checked everything, swapped the cameras around, switched the door sensors around, reconnected everything. It works fine for a day or two then we’re back to square one.

Anyone shed any light?

Edit to add, is there a test function, a way of telling what’s wrong?