When we ask for photos, it is best to provide them as we may be able to see something you can not.
If the alarm box is closed and you reset the system. then do a walk test does the tamper light illuminate, if it does and you press OMIT which LEDs are illuminated?
This will tell you where the tamper is coming from should be (1) Bell or global tamper circuit.
There can be more than 1 tamper on the system.
most common is (3)lid tamper meaning the lid id not on properly on the keypad or panel.