Cannot access stock on an item that was converted to Batch tracking after initial stock was added

Cannot access stock on an item that was converted to Batch tracking after initial stock was added

We are currently testing Inventory and I stumbled upon something "weird".
A created an item and put some stock (100 pcs) on it. After that, I enabled batch tracking on this item. Again, I added stock, creating a batch (500 pcs) in the process.
Now for the interesting part: when I sell the item, the item shows a stock of 600 (correct), but when I enter a sales amount, I can only select stock from the batch (500). The initial stock amount, before setting the item to batch, is not accessible anymore for sale.

I do understand that this is an "edge case", but this means that if anyone should decide to set an item to batch mode, after using the item without batch, your stock gets messed up.

Ideas/experiences, anyone?

Thanks,
Rob