What’s this? 79V?
My RBSXTG-5HPnD-SAr2 with 6.24 show this strange /system/health value.
With 6.1 (default) they show 124V and with 6.18 they show 11.9V and 23°C that is something correct.
I made “upgrade firmware” after system upgrade, obviously.
How can I solve?
Thanks
Do you upgrade the RouterBoot too?
If you have not upgrading RouterBoot after RouterOS upgrade, run this command:
/system routerboard upgrade
and then reboot your router.
And that was your mistake 
, see 6.23 - system health - is not working properly.
I upgraded the RouterBoot and now it’s 3.19, so Sob is right and it isn’t really my mistake, but something wrong with routerboot 3.19. I’ll downgrade where I need it. Thanks.
we were able to reproduce this and will make a fix in the next RouteBoard firmware.