Update issues.md (#189)

* Update issues.md

* Update _docs/floodgate/issues.md

Co-authored-by: Kas-tle <26531652+Kas-tle@users.noreply.github.com>

* Update _docs/floodgate/issues.md

Co-authored-by: Kas-tle <26531652+Kas-tle@users.noreply.github.com>

* Update _docs/floodgate/issues.md

Co-authored-by: Kas-tle <26531652+Kas-tle@users.noreply.github.com>

---------

Co-authored-by: Kas-tle <26531652+Kas-tle@users.noreply.github.com>

_docs/floodgate/issues.md

@@ -51,3 +51,9 @@ To completely mitigate this issue, disable `perform-username-validation` in the
 At this time, there is no way to run Floodgate on servers that mix Forge and Bukkit or Fabric and Bukkit (For example: Magma, Mohist, and Cardboard/Bukkit4Fabric) - most hybrids do not support the complicated procedures we need to do in order to allow Bedrock players to connect (for the technically minded: these server softwares typically don't support NMS). 
 
 If you wish to use Floodgate in combination with hybrid servers, we recommend putting these servers behind a BungeeCord or Velocity proxy, and running Floodgate on the proxy.
+
+## After enabling global linking in offline mode, player data is not synced between Java and Bedrock players.
+
+This occurs in offline mode because the UUID of the Java account linked to the Bedrock account does not match the online mode UUID returned by Floodgate's global linking server.
+
+When using global linking, ensure `online-mode` in `server.properties` is set to `true`. Otherwise, Bedrock players will not be authenticated with the same UUID they receive when playing on Java Edition, resulting in lost progress. This does not occur with local linking.