Ms. Pacman/Galaga 20 Year Reunion, high score saving problem

[Jack104]

Recently got a coin-op, arcade version of this machine, and it's
having trouble saving high scores in memory. For instance, I'll play
Ms Pacman, beat the high score, while I'm playing the high score
display continues to increase showing I have the current high score.
After game is over, high score still displays. Then, when I press
start button to start a new game, high score resets to the default
10,000. Or, if i turn off machine and back on, high score resets
too. Similar issues on Galaga. Now, the damndest thing is that I did
get it to save my high scores one time on Galaga and on Ms. Pacman, so
it periodically works. I've been trying to reproduce the successful
save to no avail. I've been through the manual and machine settings,
there's only one option relating to high scores "clear high scores"
which is a one time clearing. The machine saves all other data fine
(audits etc). It has ROM version 1.03. Anyone familiar with this
machine seen this issue before? Is there something wrong or do high
scores work in some crazy way on this machine that I can't figure
out??

Thanks for any insight,
Jack