Anchoring apps and their daughters to one desktop

[jimwg]

Greetings!

I have ten desktops, usually with Thunderbird in one and Firefox in another. When I click a browser link in Thunderbird, the requested Firefox page appears in Thunderbird's desktop instead of Firefox's. How can I keep daughter links of a app anchored to the desktop of that app only?
Thank you & keep up the great work!

Jim in NYC

[Patrick]

Try "Settings > Plugins and Extras > Behavior of windows on other desktop".