I have a GFCI outlet on my lawn that is connected to a transformer which powers a 12V low voltage line for landscape lighting. During the last few days, the GFCI is tripping constantly (in all kinds of weather, including dry weather). I will reset the outlet, the lights will burn for a few minutes, and then it trips again and the lights go out. Why might this be happening and what fixes can I try. thank you.

Maybe the landscape/transformer is bad.....Unplug the transformer and try another electrical device and see if the GFCI holds.......

Bugs get in the box and mess with the GFCI.....

and sometimes the GFCI just needs replacing.....

"......measure Once.....cut Twice....
throw that one away and cut a new one...."