I had the same problem but with polylang, and the solution was so easy…
3- Scan new strings of plugin with WPML theme and plugins location….
I think that may be the problem.
I don’t know how it works in WMPL, but in Polylang you can filter/scan the strings or search them manually. When you do it manually is when it works.
That way I resolved my problems with Polylang, I hope that the same solution applies to WMPL!
