Find it strange the last few broadcasts that FR24 received had no location data.
The last three ADS-B data points from FR24 were:
23:12:04 3.990 s 110.226 e
23:12:34 2.990 s 110.226 e
23:12:37 2.990 s 110.226 e
All the prior data points (before 23:12:04) were just a few seconds apart and they each had a distinct position. But the last two here kept the last position from 23:12:04, also, there was a thirty second interval between the last "normal" data point (23:12:04) and the next one with no position update.
From what I know, FR24 works with predictive data at times. So these last two data points might be generated by FR24's software and not QZ8501. (This is just a guess on my part.)