False "not enough spirit" indication, possibly related: Cannot level up spirit gem

I have Mirage Archer (spirit reservation 60) slotted in, my total spirit is 32 and I have A Solid Plan assigned in my Tactician ascendancy. Skill works (reserves 30 Spirit as expected) but there's a red exclamation mark next to it and a warning that I don't have enough Spirit. This is not an issue in practice, except that when I try to level up the gem, the game acts like I don't have one. I can make a new one at a higher level, but that requires upgrading the links all over again (for each new level).

An obvious solution, that seems to not be implemented, is to use the uncut gem directly on the Mirage Archer gem itself - however, the game insists that I use the skill selection popup.

Edit: after gaining more spirit and slotting more spirit gems, which in total also demand more Spirit, but are within the limit because of A Solid Plan, there is no more warning. Seems like there's an initial check done on a skill and if its reservation exceeds the character's Spirit, it displays the warning without taking any reservation amends into consideration.