DayPilot cell can't handle three areas

Can you please post an example that reproduces the problem? You can generate a blank project at https://builder.daypilot.org.

It's worst case scenario. I've tried blank project and it's not your bug it's bug in my app. :\
Something caught my eye (and maybe that is the problem) i see that areas is now part of "properties" property of Cell class, but because my app is old like two years i think i had to create Cell class like this:
export class Cell {
areas: Area[];
resource: string;
start: DayPilot.Date;
end: DayPilot.Date;
cssClass: string;
html: string;
x: number;
y: number;
unavailable: boolean;
}
And i'm using this areas property to create areas. Do you think maybe this could be problem or i need to investigate more? Thanks and sorry for bothering you.

If you use an old version of DayPilot, I recommend upgrading to the latest release.

The "areas" property directly in Cell is a legacy location which is not part of the TypeScript definitions but it's still supported - that shouldn't cause the problem.