Courses and course formats

Hello,
I am using moodle 3.10 and the last version of grid format (3.10.0.1).
Everything was working fine when I saw something appearing on my images (different in editing and visualizing modes -web).
When I tried to understand, I realized that there was an option ("Show new activity notification image default") selected by default to yes.
I thought, I would have just to set it to no and get back to normal.
But I realized that the notifications stayed anyway and were different from one view (only the first image tagged) to another (four images tagged) as you can see in the two screenshots below.
first screenshot : [url=https://ibb.co/mqMm2XP][img]https://i.ibb.co/58fdSnJ/Screenshot-in-editing-mode.png[/img][/url]
second screenshot : [url=https://ibb.co/t4K6d36][img]https://i.ibb.co/6mwSdNS/Screenshot-in-web-mode-anonymous.png[/img][/url]

May be I missed something.
Any help would be great.
Thank you in advance.