Kickr: clunky/clicks in lowest 2 and highest 3 gears

Hello - new here. I just got a kickr smart trainer. I have a cervelo p3 on it. Seems to work well, but when the chain is on the lowest 2 and highest 3 gears on the cassette there is a clunky clicking noise that does not happen on other gears. This is not a “noise while shifting” issue but rather if on those gears as long as I’m pedaling it’s clunking. Any suggestions? ( Emailed support and they told me it was read derailer issue if happening while shifting which it is not and to contact a local bike shop - bought it thru them directly not a bike shop)

Sounds like an indexing issue. You might need to add (or remover) a spacer on the trainer hub so that it lines up more closely with your bike casssette. I have an extra 0.5mm spacer on my trainer for the 10 speed bike I have on it…extra beyond the 1mm recommended spacer.

Hope that solves it for you