Trailer Connection Indication is flashing

I recently installed a bed camper and wired the camper lights (brake, park, reverse and turn lights) using the 7 pin T connector. I tested all the connections using multimeter before the final connection and everything worked fine after the connection.
The next morning, the trailer connection indicator was flashing. I haven't checked the fuses yet, but the first thing came to me are the LED lights on the camper (low resistance) just like the issue with hyper flashing when using LED bulbs on the turn signals?

There is no brake controller warning, it is just the trailer connection indicator turning on and off every half a second. Anyone experience this before?