The bug
Text formatting is not working correctly for right-to-left text in right-to-left languages. The position of the formatting character is reversed breaking the formatting. Additionally a "r" appears in front of the text which is likely used to reset the formatting but the formatting character for it appears to be placed incorrectly as well.
How to reproduce
Change your language to a right-to-left one, for example Arabic (first right-to-left language in language list)
Use the following command
/tellraw @a ["",{"text":"في يوم من الأيام ، كان ","color":"gray"},{"text":"ناصر قيمر ","color":"dark_green","bold":true},{"text":"يلعب ماب باركور","color":"gray","bold":false}]
Related issues
relates to
Attachments
Comments


The letters not being connected is MC-35765, please change the report to be only about the "r" in front of the message which appears for other right-to-left languages as well

Can you please add the exact command you use as well?

/tellraw @a ["",{"text":"في يوم من الأيام ، كان ","color":"gray"},{"text":"ناصر قيمر ","color":"dark_green","bold":true},{"text":"يلعب ماب باركور","color":"gray","bold":false}]
here you go ( i used a tellraw generator )


marcono1234 : nice , this is a lot better

Confirmed for 1.13.1.

confirmed for 18w49a

this issue is no longer present in 1.16 rc-1

Closing as "Cannot Reproduce" then