🇺🇸United States @ljwilson

We just migrated a production site from 10.1.8 to 10.2.6, and noticed for one of our custom blocks the contextual nested links were overlaying on top of each other. I tracked it down to this change:
core/modules/contextual/js/contextual.js

I asked Chat-GPT what the difference might be, and it recommended adding 'px' since the version in 10.1.8 probably interpreted it as pixels but the 10.2.x version does not. Adding the units of 'px' fixed the problem. My change below:

diff --git a/core/modules/contextual/js/contextual.js b/core/modules/contextual/js/contextual.js
index 52fb138e9..324fe7766 100644
--- a/core/modules/contextual/js/contextual.js
+++ b/core/modules/contextual/js/contextual.js
@@ -72,7 +72,7 @@
 
       // Adjust nested contextual link's position.
       $nestedContextual[0].style.top =
-        $nestedContextual.position().top + height;
+        $nestedContextual.position().top + height + 'px';
     }
   }

Looks like multiselect 2.0.0-beta4 r changed some var variables to constants. For the error above, try changing the const to let for the $submit in line 11 of multiselect.js (with the patch already applied, of course).

That worked for me.

I've attached a re-rolled version of #6 which includes this one-word change.