Zero problems in any of the major supermarkets in my area in the South East. My food bills haven't increased notably either, if anything, looking at my bank statement right now, they seem lower over the past 4-5 months than the year before.
The only anecdotal thing I have noticed, is that there a few new brands on the shelves that weren't there previously, but that's probably just observational and confirmation bias, because I was looking for something, I saw it.
Just the usual scaremongering.
I also shop at Tesco and the stocks haven't changed at all.
Still, why even have brexit if we're going to do our level best to pretend we're still in the EU as hard as we can. Is being subject to full export restrictions, hammering British businesses, while allowing many European goods to flow in un-checked really the brexit you signed up for?
Aldi, Lidl, M&S, Morrisons and the local greengrocer all seem the same as usual here.
Are you in a really shitty area or something? I only saw what you described in the first week of lockdown one. Nothing has noticeably changed in my local Morrisons for the last few months.