If you use chisels for blocks, the red outline disappears, and functions such as Drawn Region and Line do not work.
The 1x1 chisel also does not work if the mouse is pressed continuously.
I'm using the fabric version

• MC Version: 1.18.2
• C&B Version: 1.2.87 to 1.2.90
• Do You have Optifine: both with and without

I think the reason why the red outline doesn't come out is because 'Iris' mode is used.
I checked it myself, but it is confirmed that the red outline does not appear only when it is in the mode file, regardless of whether 'Iris' is used or not.

I checked the other parts where the function doesn't work
In the case of 'creative' mode, the function has been found to be inoperative.
In 'survival' mode, the function is confirmed to operate normally.

All chisels have been used under the same conditions, but only damaged chisels work normally, and new chisels don't.

Even in the case of 'creative mode', it is confirmed that the function is functioning normally if a chisel with even a slight damage to durability is used.