Can't speak to the Anna, but my MCs (Dynavectors) and MMs (mostly Ortofons) never needed any warm-up once they were broken in (50+ hours or so). Waiting for the rest of the electronics to warm up is probably more important. My system doesn't really produce full fidelity for 45 minutes or so. Try warming up your system with some low volume non-analog source and see if you perceive the same effect in the cart. Have fun & happy listening!
How long before your cartridge warms up?
Wondering if people would share how many sides of a LP must be played before they believe their cartridge has warmed up and is on "full boil" so to speak. My Ortofon MC Anna seems to like about 2 to 2.5 sides of an album (e.g. 33.3 rpm) before it really comes to life. This is something I am just starting to notice as I am fairly new to analog.