Put the summary of the bug you're having here

What I expected to happen was...:
I place and program a command block eg: Repeat/Unconditional/AlwaysActive/no dely: /tp @e[type=npc,name=orangelord,tag=ORG] ~ ~1 ~ the npc will seemingly float above the command block and thats what you expect. 

What actually happened was...:
For un unknown reason, the command blocks stops functioning and the npc is not continuously teleported as per the command. However, this is not specific to any one command block type, repeating, chain or impulse, or what the code is. It can happen to any command block anywhere in the world, but mu observation is that it seems to be command blocks that are similar to others in use at the same time, for example the same code as the example i have given, except for a different npc name eg, npc, name=blacklord,tag=BLK. I have at the moment 6 npc's that are positioned in the same way, wach npc has a different name and tag. (the video shows this in detail)

Steps to Reproduce:
1. I do not know what triggers the random command blocks from functioning.
2. But it might be the operation of command blocks similarly programmed as described in the previous section.
3. I was an operator on another realm which had a teleportation hub, and the same thing happened in that realm, where the teleporting command blocks just randomly stop working. but when you datapick a command block and replace it, it starts working again. (the video shows you this, I trimmed the video to make it fit in 10mB)