All of my command Blocks contents are now Empty. This update removed all commands within every command block of my world. i have a backup still, but only the backup on 1.12 will still have the commands.

Update 1

I have discovered that the Commands are working fine when im playing Local, but will be empty/not working when i upload the world to my Realm and play it on the Realm.

Not All command blocks are affected, only one specific 100 block Pillar of command blocks are affected

 
Update 2

The Command Blocks that are affected will also not allow me to alter or enter new information, only when i destroy the command block and then replace it will it allow me to put new commands, even though the bugged state has no information.

Update 3

I have now discovered that the same Realm World wont let me change/add/alter the information of any commands within it even if i place down new command blocks. it lets me change their state from Repeat/Impulse/Chain but not the Info or Active/Inactive