First off, unless you have something in the way, your Rx Power for your radios shouldn’t be more then 1 dB apart. How are the antennas mounted?
Looks like you have some really clean spectrum, but sometimes that can be deceiving. Any other links in the area that you are aware of?
How much bandwidth are you trying to push across the link? You might try a smaller channel, also try turning off Auto Everything, leave your TX power at 4 dBm and go down to 2 20 MHz wide channels and see if that clears things up.
If DHCP isn’t necessary you can also try using static addresses on both sides of the link, though I don’t think that will be of much help here, but you never know.
Just some ideas to help isolate the problem.