Use of non-standard relation.

[jevolk]

The use of relation rel_type of pong Introduced by e9b4cd4 and manifests substantial bugs is non-standard and not approved for use.

It is entirely to do with them using a non-standard relation.

Possible considerations for abatement:

• Apply for standard approval of the relation.
• Replace with a pre-approved relation.

[tulir]

The exact relation type isn't relevant, it's just a bug in element's thread handling that happens with any relation type, including standard ones like m.reference. The rel_type was also already changed to xyz.maubot.pong in 4ade107 to follow the spec on custom types