I receive a specific amount every month to a card that can only be used in restaurants and supermarkets.
I don't spend everything I have there per month and I don't want to allocate the money from that card to categories I can't use it in, but putting increasingly growing amounts in groceries and eating out seems odd...
I don't know what to do, any suggestions on how to approach these cards? Has anyone ever dealt with something similar?
Should I just create a category for it and then move money from it to groceries and eating out?
Many people have this issue, typically under the guise of a "gift card" that is specific to a store. If the amount in question is small relative to the rest of your cash on hand, most will ignore the fact the money on the card cannot be used for anything, make an on-budget cash account for that card, and just budget those funds anywhere in the budget. Basically, any dollar you spend on Groceries/restaurants from the card is a dollar that you don't have to spend from real cash. When new money comes in, categorize as To Be Budgeted as is done with all new money.
This would be an issue only if you spend all your real "any-purpose" cash and based on category balances, you'd think there is money to pay the rent when there isn't.
If the amount is a substantial amount compared to the rest of your cash, then leave it out of YNAB entirely. Some people try to bring it into YNAB and synchronize a category to that account balance. IMHO, that's just asking for trouble, since this use-case (by definition) cannot afford a mistake.