Hello, at first I already searched with "conditional" for the same or other kinds of my issue.

Chain command blocks ignore the conditional / unconditional state, I have 1 example with:
"scoreboard players set @p[x=-164,y=60,z=14,dx=84,dy=24,dz=128] lever 0"

connected with:
"bossbar set minecraft:amount value 0" (Picture 1 to 3) and the problem is now, the first command was executed successfully, but the bossbar command not (at this time stamp, bossbar was not 0, so it should be set to 0)

If I re-build the same construction vertical (picture 4), it work.