Hello,
I found the issue, the problem is happening when the Embedpress plugin is enabled, so there seems to be a conflict. error is below.
Uncaught ReferenceError: EmbedPress is not defined
at paste_preprocess (post.php?post=56561&action=elementor:97)
at tN.<anonymous> (wp-tinymce.js?ver=49110-20201110:27)
at vp.c.fire (wp-tinymce.js?ver=49110-20201110:3)
at tN.fire (wp-tinymce.js?ver=49110-20201110:3)
at d (wp-tinymce.js?ver=49110-20201110:27)
at q (wp-tinymce.js?ver=49110-20201110:27)
at G (wp-tinymce.js?ver=49110-20201110:27)
at Tt (wp-tinymce.js?ver=49110-20201110:27)
at Dt (wp-tinymce.js?ver=49110-20201110:27)
at m (wp-tinymce.js?ver=49110-20201110:27)
post.php?post=56561&action=elementor:97 Uncaught ReferenceError: EmbedPress is not defined
at paste_preprocess (post.php?post=56561&action=elementor:97)
at tN.<anonymous> (wp-tinymce.js?ver=49110-20201110:27)
at vp.c.fire (wp-tinymce.js?ver=49110-20201110:3)
at tN.fire (wp-tinymce.js?ver=49110-20201110:3)
at d (wp-tinymce.js?ver=49110-20201110:27)
at q (wp-tinymce.js?ver=49110-20201110:27)
at G (wp-tinymce.js?ver=49110-20201110:27)
at Tt (wp-tinymce.js?ver=49110-20201110:27)
at m (wp-tinymce.js?ver=49110-20201110:27)
at tN.<anonymous> (wp-tinymce.js?ver=49110-20201110:27)