The 5G frequency band always works on channel 52, so there should be no influence of DFS.You need to check if it is radar detection causing it for you or the same bug as being discussed. If radar detection, it is normal and there are scripts available in the forums to have it retry 160 every so often. But that can result in downtime each time it does it.
In reality, for many users 160 just isn't practical since so much will cause it to fail back to 80. Considering you can get close to a gig on 80mhz AX and 160 has shorter range, do you actually need 160 and the headache that comes with it?
Since I want to access LAN devices at more than 1Gbps, 160mhz is the only option.