Battle shop SG not refreshing?

I bought the first weekly SG option in the battle shop last week (the cheaper SG) and when I went to the shop this week after maint, the option was still greyed out (0 items remaining), and only the second option was available (though I don't have the coins to buy them on hand atm), though it should have reset during maint.

Do you need to buy all the SG in the shop for the SG to actually reset? If so, why make some SG cheaper if you're gonna have to buy all of it eventually anyway?

My casino SG reset fully, but I buy all the SG there each week so I don't know if it's the same deal or not.

Battle Shop resets some hours later because someone made a little mistake.

Good to know, then. Weird that it says it resets at wednesday 04:00 anyway then, surprised that doesn't just pull from whatever timer they use.