That's annoying, I got into the nether world between allowable words and words that could be an answer. The bot thought I had one word left after two rows, but in my third row I chose another word that was allowed but was maybe a bit too British to be an answer...
The bot strategy of going hard to locate common letters when you get them as yellows worked out for me today, although I had a choice of 2 on line three and got lucky.
It likes words like TENET and REFER if you get a yellow E,T,R etc early on, today I did REFER in line 3 but the bot preferred REBID which may have been more tactical but less helpful for this particular target