At 19:54:55 kernel crash happens. That for some reason forces system to change time to Aug 24 1978.
systemd reacts to that situation strangely, which puts system under unresponsive state, like infinite loop, potentially causing 100% cpu occupation (this is guess now)
The printouts "Aug 24 07:45:10 ptc_lab_collab3_node17 systemd[20635]: Time has been changed" follows many times per second until node is rebooted manually.
The kernel version: 4.19.50-sunxi #5.89 SMP Fri Jun 14 01:50