[Question] Lead channel guitar: hum and signal interference grows, ends up killing overdrive, almost sounds like the clean channel. Unplug cable from guitar and plug back in and it goes back to overdrive with minimal interference. The cycle lasts for about 5-10 minutes. What do?

Guit: 2022 Gibson SG Modern Amp: 2003 Marshall JCM 2000 TSL 122 So, the inference is the regular stuff, 60 cycle hum, as it builds in intensity, there’s light radio signal interference. At the end the overdrive practically disappears until the cable is unplugged from the guitar jack. I looked in the guts of the guitar and didn’t see any loose grounds or connections. Any ideas on what is going on? Thanks in advance!