No crank no start car alarm going off randomly

What is your question?

My 2010 Ford Flex limited eco boost won't start. The alarm kept going off randomly and draining the battery. We had the battery and the starter tested eveeybwas ok. We've tried starting it multiple times. The anti theft light was flashing rapidly when the battery was left plugged in. We currently have the battery disconnected so the alarm won't go off randomly. please help!!

What makes this problem better or worse?

Nothing no crank no start

How long has your 2010 Ford Flex had this problem?

4 weeka