Since 1.13.0 anvils are only able to repair a small number of things before they break - sometimes it is as few as four!

In one example, I repaired my bow on an anvil that been used 10-15 times - anvil broke, I replaced it with a freshly built anvil and grabbed a set of four Looting1 books, combined those up to Looting 3, then combined two enchanted tridents and it broke again... three books and a trident shouldn't break an anvil, should it?!?

I haven't tested it in 1.13.1, but then I'm running out of iron as I've gone through about ten anvils in the last week and I don't dare try to build an iron farm given how buggy everything is right now;