Erg mode lag

Hi guys , whilst doing a training plan my erg mode has a lag of around 30-60 secs . Today’s workout I had to go from 140w @ 90 rpm to 165w @ 65 rpm . It would take me nearly 70 secs for me to reach 165 rpm and the same going back ton140 rpm . Please see photos

That’s if they open . Also I had the same problem in a WTRL race on Tuesday , my watts going up the corkscrew didn’t go up till I got to the top and started the decent .
Any thoughts ? TIA