My experience is that if you fly in altitude hold mode, about 2000-2400 feet AGL on the RNAV approach, you should be ableto click APR when the glideslope indicator becomes visible on the HSI, and at the same time the GPS will show LNAV or LNAV+V.The AP will capture and follow the glideslope just fine. Just make sure you are on a stable approach before hitting APR.... and at a reasonable speed, like 120 knts with gear down and one notch of flaps.Your screenshot shows a 30-degree bank which is not consistent with the recommendations above.. and no altitude hold selected..and.. it looks like 400 feet AGL...

My experience is that if you fly in altitude hold mode, about 2000-2400 feet AGL on the RNAV approach, you should be ableto click APR when the glideslope indicator becomes visible on the HSI, and at the same time the GPS will show LNAV or LNAV+V.The AP will capture and follow the glideslope just fine. Just make sure you are on a stable approach before hitting APR.... and at a reasonable speed, like 120 knts with gear down and one notch of flaps.Your screenshot shows a 30-degree bank which is not consistent with the recommendations above.. and no altitude hold selected..and.. it looks like 400 feet AGL...

Thanks Bert. I spent all weekend, and still trying to figure it out, but no avail. I tried almost everything but could not make AP to capture GS. Do no take the screenshot as reference, because it was the moment after AP gone mad.The only thing left to try, is stable approach. I will try to stay at 120knts, and below GS, above MDA. Then let you guys know.

Bert thank you very much. It works now. As you said, stable approach and reasonable speed did the trick. AP captures glide slope perfectly.Also thanks Ryan for sharing your time and helping out. Cheers