Have you turned off the device's autobrowse? Turning this off improves performance overall by ignoring small changes in the PLC, but breaks comms if you make major changes.
Choose.
(If that's not it, you may need support to look at your situation.)
IIRC, there are AB firmware versions that don't reliably report changes on download and/or small changes. You probably need IA support to help you check that.
(My alternate driver deals with this differently, so I haven't paid much attention.)