did you say you have Unifi APs? If so, what firmware?
I saw that too, thanks. I have all Unifi Ap-AC-Pro with 188.8.131.5222 firmware. I have the same experience with all firmware versions. I went back about ten revisions.
I've been having some network performance issues at home since upgrading to 4.0.69.xxx - though I didn't put 2 and 2 together until I was researching fixing my Cloud Key and ran into that thread.