Outdoor motion activated flood lights issues

I have 3 sets of motion activated flood lights on the back side of my house and for a while they have been screwing up. 2 of them turn on with motion at night but they flash in and off like a strobe light. One of them turns on whenever it’s dark and stays on, b now has begun to have the same strobe effect.

I’m finally getting off my lazy arse to fix them, but was wondering
1.) what the main source of the issue may be?
2.) should I just replace the 3 of them as opposed to trying to fix them?

They aren’t fancy, pretty standard looking, but it’s obvious that the lights themselves are LED’s and not some standard, easily replaceable bulb. I’m thinking of replacing all 3 with a motion activated fixture that I can simply unscrew and remove the bulbs from.