Update on this folks..
I've noted that cycling issues may be location related.
The other day I was in Dryau Chraei and wanted to plot all AA-A H in another sector (Zuniae) by cycling through in the GalMap.
No joy if I entered Zuniae AA-A H and hit enter. Removed H, no joy, removed AA-A and started cycling but errored at (if memory serves right ) around AA-A H100.
Finished my meandering in Dryau Chraei, scooted across to Zuniae and, for some reason, cycling now works as "normal" - I can go to GalMap, enter Zuniae AA-A H and cycle to my little heart's content.
I can also do my usual process of cycling through 'decades' of starts using Zuniae AA-A H1 (gives expected result of 1,10,11,12,13,14,15,16,17,18,19, 100 etc).
Appreciate it if someone not in Zuniae can try and let me know if they can cycle through AA-A H stars in Zuniae..