Windows 11 25H2 "Point in time restore" seems to reset System Protection to 2%

Supplement (follow-up): confirmed - the Restore Point max is forced to match Point-in-time's stored value

A follow-up test settles whether the reset is a hardcoded 2% or simply Point-in-time's stored allocation being re-applied. It is the stored value:

• I set Point-in-time's allocation to 15 GB, then set the classic System Protection "Max Usage" to 29.3 GB (6%) through the normal UI. vssadmin list shadowstorage confirmed the shared Maximum was 29.3 GB.
• A day later, with no action from me, the Maximum had been forced back down to 15 GB - Point-in-time's stored value - not the 2% default (which would have been 9.76 GB).

So the earlier resets only landed on 2% because that was Point-in-time's default stored allocation. Whatever value Point-in-time holds is forced onto the shared Restore Point maximum, overriding whatever I set in classic System Protection. In practice the System Protection "Max Usage" cannot hold any value different from Point-in-time's stored allocation - Point-in-time's number wins on the next reset, and restore points are purged to fit.

Practical upshot for anyone hitting this: set the size you actually want in the Point-in-time UI (Settings > System > Recovery), not the classic System Protection slider - that's the value that gets re-applied, so it's the one that sticks.