I have never had them cancel IFR unless I fail to respond to commands. In the case I’m talking about, you are minutes away from an approach. The ATC occasionally says “please expedite your climb/descent to XXX”. I ignore that. But if they say, change frequency or turn right/left to heading ??? then of course you respond.
The only command you should ignore is the “expedite your climb/descent”. If you’re still getting IFR cancelled then record the session or take extremely detailed notes and contact me to help.