Some resorts\cast members are charging the room balance on the credit card you place on file while doing online check in, very early the morning of arrival. you then find out when you appear at the front desk to pay off balance. They then take your method of payment, and credit the charge card. The bank that issues the credit card can take up to 10 days to clear a charge. In addition there is the $100 hold for incidentals. This is for room only reservations.
If you have a package, your reservation must be paid in full 30 days before arrival. If you do online checkin, the resort\cast members have been putting the $100 hold for incidentals before you arrive.
Then there seems to be different ways Disney is adding extra holds. The problem is that holds can be released by Disney immediately, but it takes banks days for a hold to come off. Meantime, the guest keeps charging to magic bands, more holds by Disney, applied to credit card. Disney drops hold and charges card. Bank still has hold (up to days) and processes actual charge. As long as the hold hasn't been dropped by the bank, it's effecting "available" balance.
We aren't doing online check in this time (something we usually do) to try and avoid anything going against a credit card. Here, is something we are waiting to see, because we did dining reservations (and needed a credit card for the "no show" cancellation fee), if they use that card to place a hold for $100 for incidentials.
We personally don't use our magic bands for charging purposes. We prefer just to handle everything when purchased. That way I can keep up with our spending and make sure we stay in budget (just a personal preference).