Tacx antares adjustment

Hi, i have some 2nd hand Tacx antares that i’ve used a bit but want to use more for race warm ups. Thing is, the rubber band loop seems too tight and/or the securing mechanism not tight enough and it pulls the rollers into a shorter position than i need for my MTB. Has anyone else had this issue? I’ve tried the loop on both sides of the roller as well as adjusting the nut underneath which helps create the length.