Meginord's Girdle Rawhide Belt Calculating Charges Incorrectly

I equipped the Meginord's Girdle Rawhide Belt while I have a Health Flask with the following stats:

Consumes 10 of 65 Charges On Use

The MGRB has the boon of:
50% Increased Flask Charges Used
100% Increased Flask Charges Gained

When I equip the MGRB my flasks uses go from 6 to 4.

If I'm understanding the math correctly, it would seem that the 50% Increased Flask Charges Used is being applied, but not the 100% Increased Flask Charges Gained.

Faulty Application:
50% Increased Flask Charges bumps charges used from 10 to 15 and does not apply the Increased Flask Charges Gained. This results in 65/15 = 4.3333+ (4 uses)

Expected:

50% Increased Flask Charges Used = 15 Charges Used
100% Increased Flask Charges Gained = 130 Charges

130/15=8.666666666666667 (8 uses)

Conclusion:

It appears the calculation is being applied incorrectly and results in 4 uses rather than 8 uses. Perhaps I am misunderstanding the way boons are applied?

System and Game Version:
PS5
Version: 1.010.000

I think I may have misunderstood what Flask Charges Gained means. It seems that the "Gained" is more about gaining charges from defeating enemies. Is that correct? If so, this makes perfect sense now. Apologies for eating up your time on this.