with the game update there was a problem with a command such as "/give @a[tag=item,tag=!not,scores={item=1202}] snow 1" and all old command blocks with tag are not taken into account
Thus, the command is not executed correctly and looks like this:
"/give @a[scores={item=1202}] snow 1"
and now to fix my command blocks I need to destroy each one and re-insert the command
Could you provide a copy of the world from before the update that was working correctly?