ARMember not assigning plan after sandbox/test payment testing?

Dear WordPress community,

Im testing around with ARMember plugins I had for years but never really used (support ran out)

I have it configured on a blank site (not yet Mollie approved) with Mollie payments addon in sandbox/test mode, it seems to work fine & it shows test payments completed in my mollie dashboard, however in the ARMember backend the plan (which the test payment's been done for) don't get assigned automatically, is this normal & will this be fixed once I have it fully running (not in sandbox but in live mode) or is it normal for plans to not be assigned automatically?

Thanks in advance.