Anvil is breaking after 3-4 uses for creating / repairing enchanted items. Wiki reports anvil normally gets approx 25 uses before it fails. We've lost 3 anvils @ 3-4 uses each.
The wiki also says that an anvil has a 12% chance of cracking per use. Considering the chance to break an anvil by using it three times is 0.001728, you just got very unlucky. (I even tested this in 1.13.2 and 19w03a multiple times and my anvil broke nowhere near that fast)
This has been happening to me for months now. I have a realm with about 5 other people, and all of us are constantly breaking our anvils, and every time after 3 uses. The number of uses before breaking rarely deviates from 3, and I have noticed this on multiple worlds.
The wiki also says that an anvil has a 12% chance of cracking per use. Considering the chance to break an anvil by using it three times is 0.001728, you just got very unlucky. (I even tested this in 1.13.2 and 19w03a multiple times and my anvil broke nowhere near that fast)