The OP described the change from QR to IB as "slightly different times". Qatar's own policy here is 2 hours, anything less than 2 hours is considered a minor change and is not an involuntary change. Whereas over 2 hours opens up access to their rebooking policy as an involuntary change.

Change from QR to IB is not generally considered within their existing policies an involuntary change - if you read your T&Cs Qatar along with almost every carrier makes no guarantee of what aircraft will operate a service.

Give them some time - Qatar never coordinate operational and schedule changes with customer services having an oven ready policy, there's always a lag of a good few days, and there's a previous example where they did exactly this at HEL and moved customers back to QR flights on request.