Wall Join not working

[MKJOR]

Hello,

As shown in below photo, sometimes the wall join doesn't work properly.

My case here the Fire Rated Wall (Red Gypsum) should be continued without any penetration from perpendicular wall on it, but this wall (only yellow) I can't disallow the join (the Wall Join function it self is not working).

Thanks

[RDAOU · Accepted solution]

@MKJOR 

1. Drag the wall back to disconnect from the rated wall 
2. Then right click the end grip of the non-rated wall and disallow Join

[MKJOR]

It worked perfectly, thank you