M200 Plus – Error #2:2 Hotend: Temperature drop (FW 2.6.16)

Hi,
I have a Zortrax M200 Plus and I’m experiencing the following problem:
#2:2 Hotend: Temperature drop`
My printer is running on firmware version 2.6.16 (latest update).
Has anyone encountered this issue, and how can I fix it?

Thanks in advance for your help!