When I ran the demo in ltktest-ci just now, I got the same (mis)behavior, only in my case it was only one in twenty keystrokes that got thru.  At the same time, the entry widget in the lotsa-widgets demo worked fine.

Enabling some print statements in the entry widget, what I saw was that key events such as keypress and keyrelease were working fine, but that only occasionally a "trace" virtual event came thru. The key events would not help much since the entry field itself was not getting the keystrokes (and we still let Tk handle the actual input).

Anyway, while fussing with this the ltktest-ci demo entry field just started working pretty much by itself. I was poking around, but on unrelated stuff trying to make the demo shutdown not crash on a late timer message. (That required a small extension to the Cells API.)

Anyway, it will be interesting to see if your entry field (and your ltktest-ci execution) work given the new code in Cells and Celtk. If not or if the problem comes back I think a question to the Tcl/Tk list will be in order as to when keyevents can happen but not get seen by the widget as evidenced by the widget text and (reasonably enough) "trace write"s.

kt