On desktop, posts from mobile are garbled. It seems like one letter is remove and replaced with "xx". The original garbled post displays fine on mobile, but is broken on desktop. When a garbled post is quoted, it destroys the new post and on mobile the brokeness is replaced with another letter.
fwi, i see this quite often THIS POST brought me here; which looks to be both s and S. like the post above.
Remember the golden rule of statistics: A personal sample size of one is a sufficient basis upon which to draw universal conclusions.
Upload the computer to Dropbox and provide a link to it so others may download it to examine and give advice for repairs.