Garmin Forerunner 265 - Swim Distance

This does sound like a bug, since the swim activity in Connect is supposed to use the same units (metres or yards) as the pool size you selected.

When you look at the activity in Connect, does it show the pool size in metres or yards? If it shows pool size in yards, you should be able to fix this in the Connect website (or even the app), on a per-activity basis

1) Open connect.garmin.com and sign in

2) Open a pool swim activity which is incorrectly set to yards

3) Click the gear icon and select Edit

4) Change the pool size to metric.

For example, if you originally picked a pool size of 25 m, and the activity shows up as yards, I would expect the pool size to also be in yards (i.e. ~27.34 yards)

When you edit the activity, change the pool size back to 25 m.

You should also be able to make the make the same change in the Connect app.

The only difference here is that the app doesn't support custom decimal pool sizes, which shouldn't matter for your use case. (t does matter if you picked a pool size of 25 yards, for example, but you want the activity to be shown in metres, since you'd need to set 22.86 m in that case, and it would only be possible in the website and not the app.)