Similar issue. 17.5.1 (but has been going on for months now) Windows 10, RTX 2060, 32GB RAM, 400GB external T7 SSD for cache
Seems to be consistent that if you preview, then don't edit anything but preview again, then it seems to go into this unresponsive state where it will build the preview in RAM (green line gets filled in if it isn't already) but then AE refuses to play back the preview until you close/restart AE (and AE usually goes completely unresponsive at this point too)
Similar issue. 17.5.1 (but has been going on for months now) Windows 10, RTX 2060, 32GB RAM, 400GB external T7 SSD for cache
Seems to be consistent that if you preview, then don't edit anything but preview again, then it seems to go into this unresponsive state where it will build the preview in RAM (green line gets filled in if it isn't already) but then AE refuses to play back the preview until you close/restart AE (and AE usually goes completely unresponsive at this point too)