Excel Bug: Limited willingness to copy Lambdas from local scope

I just post here in the hope that someone from M$ takes an interest in this blog.  If you know of, or have, a way of reporting bugs to M$, please bring this post to their attention.

Background:

We maintain global Lambdas centrally.  Where we need Lambdas in the local scope, we use a simple wrap structure, like this:

Global Lambda, not meant to be called from formulas:

Private.mySUM = LAMBDA(x;y;z;x + IF(ISOMITTED(z);0;z))

Local Lambda, supplying the Worksheet "Bug" context ("Bug!Codes") to the global Lambda:

Bug!mySUM = LAMBDA(x;[z];Private.mySUM(x;Bug!Codes(x);z))

In this way, it is possible to have centrally maintained Lambdas in the local scope.  A call in the spreadsheet like

=mySUM(1;4)

will yield 5.  Hurrah!

The bug:

Although Codes is not used at all, it is important to prompt the bug.    It is defined like so:

Bug!Codes = LAMBDA(r;SAMEROWS(Bug!$B:$B;r))

And although Codes is without interest, the definition of SAMEROWS seems crucial to the bug, so here it is in all its glory:

SAMEROWS = LAMBDA(super_range,sub_range, LET( _
	subRow1, ROW(INDEX(sub_range,1,1)), _
	subRowN, ROW(INDEX(sub_range, ROWS(sub_range),1)), _
	supRow0, ROW(INDEX(super_range,1,1)) - 1, _
	INDEX(super_range,subRow1-supRow0,1):INDEX(super_range,subRowN-supRow0,COLUMNS(super_range)) _
))

Insert these Lambdas into a blank worksheet "Bug" and call the formula =mySUM(1;4) somewhere in that worksheet to get 5.

Now open a new blank workbook (CTRL-N) and COPY the mySUM formula into that workbook. 

You will not succeed.

What should happen

In the copy operation, all missing Lambdas should be pulled across.  Minor modifications to the setup will also make this happen, eg

mySUM = LAMBDA(x;[z];Private.mySUM(x;SAMEROWS(Bug!$B:$B;x);z))

succeeds.  Similarly, when we define

SAMEROWS = LAMBDA(x;x)

life is good.

Very odd.