I bought the m65 pro rbg literally yesterday. No DPI issues on first day, but it started on the second day (today). I've seen on forums (this one i think?) about a guy saying it was the wires to the DP buttons.
I couldn't figure out when the DPI bug was happening, tried playing with the CUE being opened or not, nothing seemed concrete.
With the Hardware issue in mind, i decided to slightly lift my mouse up and tap it on my desk, and bam, DPI increases. It happens 8/10 tries, so im 99% Sure this is hardware, returning for sure.