in #lubuntu-devel Krytarik suggested I try an older version
<krytarik> guiverc: From a quick web search and given the behavior, it still seems likely that xscreensaver is at fault there though. Could downgrade the packages you've got manually to the previous version here and test if it's the same with that too: https://launchpad.net/ubuntu/+source/xscreensaver/5.36-1ubuntu1/+build/12357850
logged out & re-tried, still same effect (I can view one screen which updates its windows [htop] and screensaver runs on other).
I then rebooted & retried & got same result -- screens dim for a second (a very nice effect) then one display resumes it's display of htop/hexchat etc & other shows xscreensaver...
in #lubuntu-devel Krytarik suggested I try an older version
<krytarik> guiverc: From a quick web search and given the behavior, it still seems likely that xscreensaver is at fault there though. Could downgrade the packages you've got manually to the previous version here and test if it's the same with that too: https:/ /launchpad. net/ubuntu/ +source/ xscreensaver/ 5.36-1ubuntu1/ +build/ 12357850
I installed that version
guiverc@ d960-ubu2: ~$ apt-cache policy xscreensaver 42+dfsg1- 1ubuntu1 500 ftp.iinet. net.au/ pub/ubuntu disco/universe amd64 Packages old-releases. ubuntu. com/ubuntu zesty/universe amd64 Packages dpkg/status d960-ubu2: ~$
xscreensaver:
Installed: 5.36-1ubuntu1
Candidate: 5.42+dfsg1-1ubuntu1
Version table:
5.
500 http://
*** 5.36-1ubuntu1 500
500 http://
100 /var/lib/
guiverc@
logged out & re-tried, still same effect (I can view one screen which updates its windows [htop] and screensaver runs on other).
I then rebooted & retried & got same result -- screens dim for a second (a very nice effect) then one display resumes it's display of htop/hexchat etc & other shows xscreensaver...