Error with apt-get update, elasticsearch signature is not valid

Hello ! I have an issue with apt-get update command

i am on ubuntu 20.04
and the last koa version

when i run :

sudo apt-get update

i got this return :

W: GPG error: https://packages.elastic.co/elasticsearch/1.5/debian stable Release: The following signatures were invalid: 46095ACC8548582C1A2699A9D27D666CD88E42B4

the last stable elasticsearch’s version is 7, and the openedx version is the 1.5 ! So I thought that openedx wanted to block elasticsearch’s updates on purpose.
I decided to run apt-get update excluding the update of elasticsearch

but when i run :

dpkg --get-selections

to show all packages on hold, it return :

elasticsearch hold

elasticsearch is already on hold ! So i don’t know what to do. Has anyone ever faced the same error

Thanks for your help !

Dimitri