@fenderman I have three 2831T-ZS cameras I upgraded them all to 29.4 for the latest update.
Sd card has been visible on all cameras at all times when I've gone to check.
One had a hot swap every day but only because I had auto Maintain at 1.00 hot swap appeared in the log at 1.01 every day.
Did a brick-fix tool / full upgrade method / fixup Roundup for 6 cameras.
Had ntp time for 1 minute for a few days but it did not help, i have no nvr. Upgraded all cam mod firmware and now a couple of days without any problems.