rmul means "exit underline mode", so a full reset of all the attributes is not the correct way of exiting from underline mode, because it is going to modify also another attributes not related.
@@ -161,7 +161,7 @@ st| simpleterm,
rmir=\E[4l,
rmkx=\E[?1l\E>,
rmso=\E[27m,
- rmul=\E[m,
+ rmul=\E[24m,
rs1=\Ec,
rs2=\E[4l\E>\E[?1034l,
sc=\E7,