I don't know why, but my custom advancements are reset on reboot of my server.

so when player login on server, i have this:

 Ignored advancement 'minecraft:challenges/welcome' in progress file ./world/advancements/871f191a-0637-4c6b-8115-7229c1c8332a.json - it doesn't exist anymore?

but advancements are already there. (advancement copy/paste in end and nether too)