When I switch the view to targeting pod, e.g. GBU-38 or AGM-65D/L, the aircraft immediately starts to descend.
Even if I use manual SAS mode and trim the pitch to a slight climb.
I made a bug report, if you have the same issue please click the 
button in the bug report below:
https://community.gaijin.net/issues/p/warthunder/i/DhAx48vOwUUe