Reverse effect doesn't work

does this happen on one and the same plane or on all planes?

have you tried to download the beta version? here: https://fsrealistic.wixsite.com/website/forum/general/v2-1-2-beta-patch-for-reverse-thrust-landing-applause?origin=notification

Ahh - thank you so much. That fixed it. I wasn't aware of this update. Many thanks!