Error on posting after leaving page with the "loading" bar going (5+ seconds)

[frm]

Affected version

2.3.2

The title of the thread post, but the thread view will say this to the user:

A server error occurred. Please try again later.

And this to an admin:

XF\Db\Exception: MySQL fetch error [2014]: Commands out of sync; you can't run this command now in src/XF/Db/AbstractStatement.php at line 230
[LIST=1]
[*]XF\Db\AbstractStatement->getException() in src/XF/Db/Mysqli/Statement.php at line 207
[*]XF\Db\Mysqli\Statement->getException() in src/XF/Db/Mysqli/Statement.php at line 142
[*]XF\Db\Mysqli\Statement->fetchRowValues() in src/XF/Db/AbstractStatement.php at line 95
[*]XF\Db\AbstractStatement->fetchAliasGrouped() in src/XF/Mvc/Entity/Finder.php at line 1494
[*]XF\Mvc\Entity\Finder->getCollectionFromResults() in src/XF/Mvc/Entity/Finder.php at line 1450
[*]XF\Mvc\Entity\Finder->fetch() in src/XF/Pub/Controller/ThreadController.php at line 109
[*]XF\Pub\Controller\ThreadController->actionIndex() in src/XF/Mvc/Dispatcher.php at line 362
[*]XF\Mvc\Dispatcher->dispatchClass() in src/XF/Mvc/Dispatcher.php at line 264
[*]XF\Mvc\Dispatcher->dispatchFromMatch() in src/XF/Mvc/Dispatcher.php at line 121
[*]XF\Mvc\Dispatcher->dispatchLoop() in src/XF/Mvc/Dispatcher.php at line 63
[*]XF\Mvc\Dispatcher->run() in src/XF/App.php at line 2813
[*]XF\App->run() in src/XF.php at line 802
[*]XF::runApp() in index.php at line 23

[/LIST]
However, if the user or admin hovers over the thread title in node view, it will show the contents of the thread in the tooltip.

I've tried rebuilding threads to see if it fixes it.

For now, deleting it and reposting.