In WYSIWYG editor adds " " during post editing. I have checked the option to save data in with and without "wpautop" option [save data in raw format]. In both the cases, it adds in revision of the post.
See the image for more details. https://1drv.ms/u/s!AjLgaRuebK87hqI0gsLuPw6lFQ3omQ?e=SQdq7l
I do not see that issue on my demo site. Can you please test this on a fresh install of WordPress and Meta Box again? If it still happens, please share that site credentials to the contact form https://metabox.io/contact/, I will take a look.
Hi, I finally found the real culprit: the "Chrome extension" responsible for automatically inserting extra spaces in the text editor.
Thank you very much for your support and time. Please close the ticket.