today's (12-08-2022) konsole upgrade messed prompt
 

please see attachment

looks like underscore is being turned on for the green on grey sections.
What escape sequences are you using for that section of PS1?

Prior to kernel 3.16 the linux console used to turn underscore on for \e[38m. Perhaps konsole has started honouring that old behaviour.

Also, what is your $TERM set to?

Thank you GazL for helping.
that is my prompt, no \e[38m

and
not sure what's wrong

just for testing reverted to the previous version of konsole:
konsole-22.08.3-x86_64-1 and all works, so this is definitely a problem with konsole

obviously after downgrading konsole, prompt looks as it should :)

I wonder of the new konsole thinks it fixed a 'bug'. I suspect xterm may be thought of 'doing things right'.

I tried your prompt on xterm(1), and it matches your 'bad' prompt. On Slackware 15.0, under konsole, it looks different and better, it has no underlines.

Both runs used a TERM of xterm-256color

Did you open a bug report?

Try removing the ";4" from both occurrences of \033[0;92;4m
i.e.
PS1='\[\033[0;92m\]\342\224\214\342\224\200\[\033[0m\]\[\e[42m\] \u@\h \[\e[0;32m\]\[\e[102m\]$triangle\[\e[0;30m\]\[\e[102m\] \w \[\e[0;92m\]\[\e[40m\]$triangle\[\e[0m\]\[\e[40m\]\n\[\033[0;92m\]\342\224\224\342\224\200\342\224\200\[\033[0;92;1m\]▶ \[\033[0m\]'

Thank you all.
This is definitely a bug, though I doubt that anyone will bother. I am going to submit a bug report just to have clear conscience :)

Thank you GrazL for pointing out the solution, removing only 4 will leave arrow green so I also changed
\033[0;92;1m
to
\033[0;92;0m
or replace 4 with 2 (not bold) and it works too.

No, but there is easy workaround as I mentioned above by replacing bold font with normal font. So it is possible to use normal font until bold font is fixed.