How much time take for remove a warning from fiverr profile
You can not remove fiverr warnings. They will stay with you forever.
maybe this will help - https://sellers.fiverr.com/en/article/warnings
Each warning will stay active for 90 days from the day you received it.
Get 3 active warnings, and you will lose your account.
(In some cases, one warning can lead to a permanent deactivation of your account)