Ok, after lots of ripping apart company and default acad profiles, I think I got it down to what I consider a bug.
Indeed, the replies to check auto-correct/complete were also my first thought, and I faithfully posted the pic of them off.
But it seems they are not fully off. Note that the "Mid string search" option is greyed but on:

I thought those did not matter as autocomplete and autocorrect are clearly off.
But if I open the options, turn on autocomplete so I can access the mid-string search box, and turn it off as well as autocomplete, the TRAV command does nothing.
I can repeat that easily, and I expect everyone on 2019.1.2 can, and likely all acad versions since maybe 2017.
I don't think adesk considers that a bug, but I would most DEFINITELY call it a bug.
The odd thing is, it only seems to happen on functions the first time they are defined.
I have a .lsp names LinesCurves.lsp, with one function (DEFUN C:CT-TRAVERSE ( / )....
The first time I load that lisp, TRAV runs the function (with the mid string search on).
If I rename the function to (DEFUN C:CT-TRAVERSE1 ( / )....
and reload the lisp, TRAV does nothing now, says unknown command.
If I rename it back to (DEFUN C:CT-TRAVERSE ( / ).... and load, the TRAV does nothing now too.
So the mid string search bug only happens for functions defined in a lisp, the first time that lisp is loaded.
If the function names are the same, reloading it has no effect, the bug happens.
If you rename a function and reload a lisp, it seems to clear the search of functions from that file.
This implies the search knows where stuff came from.
The moral of the story is turn off mid-string search if you don't want it, as simply turning off autocomplete is not enough. thanks for watching, all.
internal protected virtual unsafe Human() : mostlyHarmless
I'm just here for the Shelties