Command block runs incorrect commands

Command block executes incorrect command

I was creating a teleportation pad machine with a command block hooked up to a redstone clock producing signals at less than 1 tick. I realised that I made a mistake in the entity UUID (armour stand specifically). So I changed the command and it wouldn't run as expected, I tried copying the command block with its NBT tag and powered it but it wouldn't execute the command at all.

I'm not quite sure how this happened but I tried a lot of fast clocks and if you type in the command wrong the first time it won't execute commands as expected at all afterwards even if you destroy the clock.