Off-with-duration changes default on level?

I just encountered some odd behavior when playing with HA automations for my switch and wanted to know if this is expected, or a known issue.

I have a Blue 2-1 (firmware 2.15) controlling some non-smart dimmable LED bulbs. I created a very simple automation, triggered by the config button, which calls light.turn_off with the “Transition” setting set to 15 seconds:

This works pretty well — the lights turn off slowly. The issue is, when I turn them on again by pressing the up paddle, they turn on to what seems like the minimum level, not the level they were at before I triggered the automation. (Worth noting that I have changed the min/max level settings to 51 and 190 based on some manual testing to calibrate the range of brightnesses the bulbs are able to output.)

This issue was happening with the default value of 255 for parameter 13. I found that a viable “workaround” is to set it to 254 instead, so the lights come back on to 100% rather than ~1%. But of course this workaround means that I don’t get the true “turn on to last level” behavior that the default value of 255 should provide.

Is there a good explanation for this behavior? And might there be another way to achieve a “slow off” that wouldn’t cause this issue?