SEO tab Shows "0" and no info

 Hi, I have a test site where I've installed Route 66. I can get the SEO tab to show in the toolbar or in a tab in the editor form, but it only shows the box for me to type in my key word, which i do, and then nothing else. i am getting a javascript error which I'm copying here:

route66seo.js?1.5.0:75 Uncaught TypeError: Cannot read property 'onChange' of undefinedRoute66Seo.addEvents
@ route66seo.js?1.5.0:75Route66Seo.start
@ route66seo.js?1.5.0:61(anonymous function)
@ route66seo.js?1.5.0:225

I have turned off any extensions that involve the content editor (such as sp pagebuilder and irelated content), so it's just the basic editor. I'm on Joomla 3.8.10

Thanks.

Well, strangely, it suddenly started working! I don't know what changed it.
However, is the SEO tab only available in the back-end, but not the front-end editor? Because most articles are my site are created fro the front end, I need those writers to be aware of their content's SEO ratings as well.

NO! I'm afraid I spoke to soon. It worked once, for a minute. Now it no longer works. When I change the content in the "Focus Keyword" box, it also generates an additional javascript error that seems relevant:
Uncaught TypeError: Cannot read property 'val' of undefined
Route66Seo.getPaperText @ route66seo.js?1.5.0:172
Route66Seo.analyze @ route66seo.js?1.5.0:82
n.isFunction.d @ jquery.min.js?30219fb…:2
n.event.dispatch @ jquery.min.js?30219fb…:3
r.handle @ jquery.min.js?30219fb…:3

This is in addition to the javascript error I posted above.