Resistance mode easier than ERG

I’ve been in the midst of a mostly VO2 block so have been using resistance mode on my Magnus M2 (power matched to stages lh).

Today was a endurance session and forgot to move off ERG, as the requested power stepped up from warm up I was finding it harder than you’d think for the power required, after 2 sprints in ERG it swapped back to resistance. Hitting the same power is smoother and easier I’ve found with changing gears.

When the watts reach higher levels I can hear a swish each pedal stroke and it’s noticeably less smooth and almost jerky. I’m in the small front ring but the noise is the same in the big ring. Tyres slipping/squeeking noises is higher in ERG as well.

Just wondering if anyone else experiences similar. I love the idea of ERG for endurance and sweet spot but I might have to higher expectations for it.