First apologies again for delayed answers. I am running testing which is up to date.
On kernel 4.16.0-2-amd64, with command line /boot/vmlinuz-4.16.0-2-amd64 root=UUID=43ae47ae-86fc-43a6-9661-dcf030179dc0 ro tsc=unstable init=/lib/sysvinit/init the problem seems to be resolved. I would close this bug, but it seems as if others may be seeing something similar, so I leave it to the maintainers to decide whether to leave it open. ael