Different times for Webinar

[MO15]

I have created a webinar to begin at 11am GMT. This looks fine on the webinar dashboard, but when I send a link to participants the meeting says it starts at 12.0 (no time zone given) - how do I fix this so it doesn't confuse participants?

[va19]

Same issue, it happens apperently only on my LATAM events. How do I fix this?