Climb performance over FL300

I wasn't having this problem initially but now I am finding that the aircraft will not climb much above 30,000. Climbing in CLM mode at mach 0.68 or so, the aircraft slowly trims nose up and gradually loses speed. Maybe a weight and balance issue but I am light looking at the EFB performance page. Must be doing something wrong but I can't figure it out. Even when I go into ALT hold at FL270 the flight director is commanding 10 degrees nose up and can't develop any speed. 3a1948ca936d40dc8a9

Hello, I have exacly same problem after last patch, never before. Icing effect visual only, live weather but actually no any clouds around, I'm flying e.g. 10 minutes at FL350 and it's happening. Aircraft starts to slowing down and in effect drop alltitude. At this time trim goes to maximum nose up (around 15). After disconnect AP and trim aircraft manualy back to normal, everything is ok until turning AP back, then immediately trim goes up again. Sometimes after few minutes it's goes to normal