Spell check dictionary only lists up to L

[Pogo1]

I went looking and found instructions on how to edit the spell check dictionary. When I scrolled through the list, I noted that it stopped at words beginning with ‘L’. I added the word ‘zimbo’, tested that it was not flagged as a spelling error and went to find it in the list. Not there. The list ends at L. I added the word ‘frabble’, tested that it was not flagged as a spelling error and then went to look for it in the list. Not there either. Maybe there is a maximum number of words in the list? But counting them gives 41, not an obvious choice for a limit. How can I find the rest of my custom words?