R5 IBIS seemingly erratic behaviour when shooting video

Nov 23, 2020
Hi everyone,
My R5's IBIS seems to behave in a weird way when shooting video with a Canon EF 24-70 f/2.8 zoom attached (this lens has no IS). Even if I'm just "smoothly" panning handheld, the sensor moves around in short, erratic, unexpected bursts. Very annoying and of course renders the footage useless. I have tried different settings (digital IS off/on/enhanced), recording modes (auto/manual exposure) and AF methods, to no avail. Basically, I've had to turn off the IBIS to ensure I get my 4k footage jitter-free. On the (also non-stabilized) EF 70-200 f/2.8 the problem is much less noticeable. Has anyone run into this same odd behaviour? Any fix suggestions?