High Pitched whine from my light bar?

2015+ rzr 4 900 eps

Have an 8 gauge wire ran from the neg side of the battery to the grounding post on my power port under the hood. Connection is tight.

6 gauge wire ran from positive battery connection to after market fuse block.

Everything works, just have a high pitched whine like the light bar isn’t grounded correctly. The only time I can get the wine to stop is if I pull the ground wire off the power port and touch it to one of the grease zerts on the front axle. Grounding anywhere else results in the whine again. Ive tried at least 30 different spots. Pulled the light off and hooked it up, the exact same way as mine, to a buddy’s 1000 and no whine. Can’t for the life of me figure this out and its driving me crazy, so I figure I’d throw it out there and see if anyone has dealt with this before.

Thanks in advance!