Some time ago I have made a bug report on upstream that GRUB_TIMEOUT set to a non-zero value does still work in some cases even if GRUB_HIDDEN_TIMEOUT is set: https://savannah.gnu.org/bugs/index.php?41918
Probably it is releated with this bug report.
Some time ago I have made a bug report on upstream that GRUB_TIMEOUT set to a non-zero value does still work in some cases even if GRUB_HIDDEN_TIMEOUT is set: https:/ /savannah. gnu.org/ bugs/index. php?41918
Probably it is releated with this bug report.