Please check if your code conflicts with IRTweaks Bulk Purchasing

Holding CTRL or SHIFT and clicking on the - or + buttons I no longer can buy 5 or 20 items at once from thousands of items the shop has. It works in BEXT, which has no Customshops and no Dynamicshops mods, only with IRTweaks Version": "0.9.4.2".
BTA 3062:
2022/4/14 Patch v13.3: "You can now bulk purchase items in the store (hold Ctrl and click to buy 5 at a time!)."

IRTweaks mod.json:
"BulkPurchasing": true,
"Store": {
"QuantityOnShift": 5,
"QuantityOnControl": 20
},

Maybe there is a setting, a rewritten AllowMultiSell source code section in CustomShops, that PREVENTS IRTweaks from working?

Thank You.

Reproduce the shop behavior with IRTweaks 0.9.4.2 and CustomShops, holding CTRL or SHIFT while clicking the quantity buttons. Compare CustomShops' AllowMultiSell path with the BulkPurchasing, QuantityOnShift, and QuantityOnControl settings shown in IRTweaks mod.json; done means buying 5 or 20 items works again in the affected shop.

Written by the indexing model from the issue text.