I was also running into this issue. Short before the track has ended, the waveform got stuck (but sound was still OK), the CPU went to 100% and Mixxx was unresponsive.
I can confirm that this issue is already fixed in 2.3 branch (tested with commit 10e707ace5dc31fe53cf7e720fc908d8303ca5bf).
I was also running into this issue. Short before the track has ended, the waveform got stuck (but sound was still OK), the CPU went to 100% and Mixxx was unresponsive. e53cf7e720fc908 d8303ca5bf) .
I can confirm that this issue is already fixed in 2.3 branch (tested with commit 10e707ace5dc31f