Fitness Swimming Session Data from AppleWatch doesn't properly store yards and meters

Fitness app (iOS 18.1.1) not storing swim data units from Apple Watch correctly. All swims are either reported in meters or yards, reverting to units from the last swim.

I alternate swims between a 50m pool and a 25yd pool. I change the distance and units on my AppleWatch before each swim to match the pool.

Starting with 18.1.1 my iPhone Fitness app displays all swim session history using the units of the most recent swim.

For example,

Tuesday 1600 meter swim in a 50m pool gets rewritten as a 1749 yard swim after my Wednesday swim in a 25 yard pool. In fact all of my hundreds of stored swims are rewritten using the most recent units used on my AppleWatch.