ILS approach glideslope not following

[BIGGLES5098]

Hi all
I fly the TBM 850 in msfs2024 store version SU3 on a fully updated and fast windows 11 machine (AMD, RTX5070ti)

Halfway the ils approach, at mixed altitudes, say 1000ft, the autopilot GTN750 APR glideslope won't lock anymore and levels off. Result is decreasing speed on idle and stall, unless you takeover manually.

Is this a bug or normal behaviour?

thnx