Can't open water fish a saddle after >500 tries.

In over 500 attempts (verified via statistics screen), I have not been able to fish up a saddle in my world I newly created last night in 1.20 pre-release 6. The last ~150 of those attempts were with Luck of the Sea II, from a rod received as fishing treasure. I have received 3-5 each of all the other possible treasure items.