Sometimes after you've completed a Bulk Price Change, a client's appointment may still be displaying the old price (and therefore a discount at sale).
If this happens, don't worry, you can wipe the sweat off your brow and calmly proceed by
1) Editing the service or product at 'POS' to reflect the price change as you go
When you're ready to finish the sale:
1i) Add the client to sale
1ii) Click on the service(s) applying the discount
1iii) In the right-side panel de-select the original service from the 'Service' drop down
1iv) Re-select the original service from the 'Service' drop down
1v) Click 'Save' to resolve the issue
The service will no longer have the discount applied.