Problems getting my through axle to engage with my bike frame on the drive side

I'm having problems getting my bike attached to the turbo trainer. I can't get the through axle to engage with the frame on the drive side. It's a Tacx Neo 2 and I'm trying to attach my Canyon Grail. I can see the through axle coming all the way through. It just doesn't engage with the frame to tighten. I've tried adjusting the position of the bike but it still won't attach. The through axle attaches fine when I remove the bike from the turbo trainer, so I'm not sure what's causing the problem. The cassette is a Shimano 11 speed.

My Canyon Grail bike takes a through axle which is 12mm x 142mm thread M12 x 1.0. As such, I’ve used the 12 x 142 NDS adapter. The through axle goes all the way through from the NDS to the DS, protruding by almost 2cm without the bike attached, although I can’t measure how much it protrudes with the bike attached. Any thoughts on why the through axle does not engage with the frame of the bike on the DS? I’ve been reading various forums but have not found a solution. Many thanks