Can no longer repair items by combining, including crafting table

I recently performed a restore from a backup of 1.12.2 for testing. Upon restoring to 18w50a, I found that I could no longer repair or restore broken items by combining them, including on a crafting table.

 

In addition, before performing this - I played the same game at 18w49a and the performance was better. This snapshots has a "largish" feel if I may be frank.