ScriptUI oList.removeAll() tilts FM

Dear friends,

Back on stage I encounter a very strange problem. In the following short function I set up a DropDown list:

KLD_F.FillDlgList = function(oList, asListItems) { // ============
/*            Fill dialogue list from global array
Arguments     oList           dialogue list to be filled from the array
              asListItems     array with the list items
Returns       -
Called by     various call-back functions
History       2020-11-10 tested with FMfindRepl
*/
var j, nItems;
  nItems = asListItems.length;
  oList.removeAll ();                       // clear the list
  for (j = 0; j < nItems; j++) {
    oList.add ("item", asListItems[j]);
  }
} //--- end FillDlgList

It is encountered very often during executing the script FMfindRepl. Now I found that after certain sequences of operations, namely:

Find Cross-Reference (any) (2x)

Find Cross-Reference of Format ... (2x)

Find Cross-Reference (any) (2x)

Find Cross-Reference of Format ... → Zoingg

The script halts for a while in the line

  oList.removeAll ();                             // clear the list

and then FM disappears silently (no dump, no trumpets...)

When stepping through the script (having set a counter of its calls to set the breakpoint) I see that, when entering this statement,

1. First the display of data disappears in the debugger (same behaviour in ESTK CC)
2. Then after about 5 seconds FM disappears.

In the past two months I had used this function during the tests close to 100 times and it behaved. It was quite tricky to find the reason for the instant disappearance of FM in recent tests.

Edit

After introducing a statement

Console ("oList length = " + oList.items.length);

just before the removeAll line, I see this:

oList length = 0
oList length = 0
oList length = 0
oList length = 14

 Hence the removeAll fails if it should do what it is intended for...

I also need to check why in the other cases the list already emtpy.