2022 Dec, yes I know it is "late reply" , however, this problem still exists today.
I got the same error messages.
Most of what I was wearing did not rez, I had only underwear. The ctrl-shift-1 stats tool showed max bandwidth occupation, totally red.
I was at my own parcel. Then I tp'd to a sandbox, and got the same errors. The ctrl-shift-1 stats tool showed max bandwidth occupation, totally red, the same peaks.
So it could not be the region. It was clearly my own avatar with attachments. So I stripped myself completely, still in the sandbox, all clothes, huds, scripts etc everything. Then I began wearing, one by one, all what I was wearing originally.
Then I logged off and logged in the same sandbox. No errors any more. The stats showed no peak. Then I logged off and in my own parcel. No errors anymore. The stats showed no peak.
Problem completely solved!