Timestamp changed by itself his way of working

Hello,

I have a weird problem:

my pipelines file all work the same way about date:
I get the date of the event, then I use the date plugin this way:

date {
	match => [ "date", "ISO8601" ]
	timezone => "Europe/Paris"
}

it resulted on @timestamp = date
everything was perfect until today

I did not change anything but all my timestamps are now 2 hours fewer than the date field

I now have to put this timezone to get the right timestamp: Africa/Abidjan

And i'm quite lost (I checked almost every opened topic but could not find similar problem)

I'm using logstash 7.1

it is installed on a linux VM and if i us the date command I've got the CEST timezone (which is the same as Paris)

jeu. juil. 25 16:38:08 CEST 2019

Nobody have acces to this server so nobody could have changed settings without me being aware of it

Thanks in advance