Saved messages not appearing in second device

[adbenitez]

I am afraid that some messages are getting miss since 2.43.0 (desktop core is 2.43.0 but android is 2.44.0), I noticed this first in #7952 where I focused on the channel problem but as I said there, there were another account without channel where normal messages were not appearing in both devices

now it happened in the same account where I have the channel:

I saved some messages (some are videos but other are simple text messages) in android and they are nowhere to be found in desktop:

in Desktop nothing of this appears, even if the messages themselves are in the original chat, so it was the sync-messages that got lost somehow maybe while syncing after being offline the sync messages got somehow processed before the actual messages. If I now try to save some of that messages again while both devices are online, it works, here you can see desktop's saved messages after I saved a message again just now:

[Hocuri]

This may have been triggered in this way:

• The message was sent to a rather-slow relay
• Only one of your device was online, and on this device you marked the message as bookmarked
• The bookmark-sync-message was sent on a faster relay
• You turned on your Desktop device, and it received the bookmark-sync-message first, and ignored it

So, the actionable item here is to make sure that bookmark-sync-messages work fine even if the sync message arrives before the original message.

[iequidoo]

As we send messages to all own relays, i think that the fix is to not create a tombstone for a sync message if the referenced messages couldn't be found. Then, when everything is received from the "rather-slow" relay, it will eventually work. The same problem we have for MDNs (#8030 (comment)) and, obviously, for edit and deletion requests and reactions. All these messages are lightweight, so downloading them once more because there's no tombstone looks fine.