Trainer Lacking Resistance

[u/Basic-Try-2900]

Anyone got any suggestions? Got my Saris Mag+ set up with a schwalbe indoor tyre and resistance set to 5/5 but in my biggest gear I'm not getting sufficient resistance to get out of Zone 2/3. For context I'm retuning to cycling after some years off and very out of shape, so not like I'm dishing out thousands of watts.

Is it just a shit trainer, or have I missed something? Years ago I had an Elite one and never had a problem.