Certainly the transparency over the last few nights has not been 100% in this part of Cheshire. Something like a very thin veil that means the sky lacks that sparkle. this shows up in my CCD images as a high background. Even this morning the sky, though blue, lacks that deep blue.
This reduces the naked eye limiting mag, although Megrez has always been clearly visible to me.
But I suspect this is a meteorological situation independent of lockdown