Depricated Code not showing in Post Edit Visual Window

Hi Folks,

I use TinyMCE Advanced and Classic Editor and do not use blocks.

I import lots of post text from emails from others, which use a variety for formats.

Today I imported one (copy and paste direct to visual window) which contained deprecated code e.g. <b> rather than <strong> etc. etc.

If I post it out as is – it works on the browsers and bolds the text, but on the Post Edit visual window, it does not show. It only shows plain text and does not recognize <b> code.

Is there any way I can get <b> to render correctly on in Post Edit visual window, so I can see what I am doing, without having to use the Post Preview?

Regards and thanks,
Angus

PS I am using latest WP core and all plugins are latest versions.