FeedValue text and dials no longer showing on dashboard

I have a dashboard on my local that displays feedvalues and has dials and graphs. It used to work fine, but I noticed today that unless I am logged in the feedvalues and dials are missing. The graphs still display. I tried updating software - now at “low-write 9.8.28 | 2018.01.27” and rebooted with no effect.

I also notice that on a dashboard with histogram bars, the bars are outlined but not filled.

All feeds and dashboards are set for public.

Browser is either firefox on windows or edge on windows - same issues.

Any assistance appreciated - it’s not disastrous, but it is annoying.