I had that issue with one of mine after I’d cleaned it.
I took it all out, repositioned the terminal box and although it’s already water tight I sealed over the entry holes with silicone. I also drained all the flexi-con of water which had filled in there and dobbed silicone over them to stop water ingress and it lying in there.
I checked all connections which were hid out the way anyway and made sure there was nowhere that any moisture could sit.
Since then it’s not been an issue.
Also make sure your connections are secure and tight.
Some of them are designed to stay on and as there’s no resistance to draw the power they’ll stay on a little longer.
Mine went off straightaway from the first time I’d wired them in so I knew it wasn’t anything too sinister.
Maybe worth noting, I’d left it disconnected over night when I noticed it and when I reconnected in the morning it was working as previously. Hence why I presumed it wasn’t anything other than maybe a little moisture.