There can be so many reasons for your problem.
Have you generated WS after changing the PWS/DWS? For what period (from mm/yyyy to mm/yyyy). Have you generated WS for all the afftected WSR's?
One PWS may be in more than one WSR with different start date. This is a common way of configuration where two different sets of shift workers work in alternate weeks. This would change the way you'd see a particular date's DWS in the two different WSR's that use the same PWS.
After the change have you transported to all the systems/clients (Test & Prod).
Usually config is in a config client in Dev system; and testing is in another client in the same dev system. In this case the transport/s is/are copied to the test cient for testing purpose before moving the transport to Test system/client for further test like system test & UAT.
Is the client you are looking (with IT 7) same as where you changed PWS & generated WS?