Let's say I give myself a "player" and "moder" tag with "tag @p add ...". Tag added successfully, check with "tag @p list" command. Next, I create a function (a.mcfunction) using an addon. The function contains:

tag @a remove HasNetherSword
tag @a[hasitem=

] add HasNetherSword

"a.mcfunction" is activated by the command block once every 1 tick.

If I have a netherite sword in my inventory, I have the tags: "player", "moder" and "HasNetherSword", otherwise only "player" and "moder"

But if I have a netherite sword in my inventory for too long, then the "player" and "moder" tags will be removed from me, although there is no command for this.

This can happen at a random time within 8 hours, but usually happens sooner.

I found this bug in my world, and there are more functions for detecting items than I showed in the example. There are usually 4 - 7 players in this world, and the bug can happen to a random one of them who has a function-detected item.