It is not unusual for guests to pay in several instalments. Due to payment batching processes, funds may be sent to your bank account at different times and may be paid out of sequence.
For example, if you utilize Check-In Payments and your guest made an initial payment on Day 1, and a second payment on Day 23, one payment may be available in your account 2 business days after the guest checks in while the other payment may be released to your account 3 business days after check-in.