I have an order that is currently assigned to a batch. I open the order and assign it to another batch. I get a message that says "0 shipments are already in a different batch. Are you sure you want to move them to <batch name>?" I click "Yes, move these shipments" but the shipment doesn't move - it remains in the original batch, and is not added to the new batch.
I wanted to reach back out with an update for you about this. One of our developers has reached out to let us know that this should be resolved. If you find this is not the case, please feel free to private message me directly. If it is working for you, please mark this comment as the accepted solution so we know it worked for you.
Thank you for your patience while this was being addressed,
-Erin: Your Friendly ShipStation Community Manager