I placed a command block in 1.14.2, typed a command, but when I try to activate it with redstone nothing happened.

The exact command I used doesn't matter because the previous output was blank. If it where an error command or a real command, the previous output would not be blank. But in case you want to know, the command was:

"kill @e[type=item]"

(Command blocks don't require a slash, and the quotes are not included)

The bug is basically command blocks don't work.

This bug applies to all types (Chain, repeating, and regular)

MC-86846 does not describe the issue, because I tried repowering multiple times and still, same results.

I also tried toggling all the options (Needs redstone/always active, conditional/unconditional), clicking done, then toggling them again and I still get the same result. Ones I placed earlier still work though.