cambridge gives this about "in all honesty"
said when expressing your opinion honestly, seriously, or truthfully
a comment in this link (https://www.youtube.com/watch?v=TizxLEYhhQM&t=7s in comments box, not in the video) says
"In all honesty" or "honestly" implies that you're usually dishonest.
Is that true? If I use "In all honesty", I would be considered as dishonest before?