You have manually add vias. Please see: https://easyeda.com/forum/topic/Recommendation_For_Via_on_Exposed_Pad-Gy4XfxrJ1

Ok thank you. Please inform your Live Chat about that two as I got told something different yesterday! What exactly does the island function on the copper outline? It looks like it excludes two small unconncted areas, but up to which size?

* Er, sorry, I'm wrong about the via in SMD pads if LAYERS is set to ALL. They *will* have a hole through them and that hole *will* be plated. All you have done is changed a single sided `SMD` pad to an all layers plated through hole pad. * However, if you do this in the PCB Editor without creating a PCB package with the modified pads and assigning that package to the relevant symbol(s) in the Schematic Editor then when you do an **Update PCB...** from the Schematic Editor or **Import Changes...** from the PCB Editor, *you will lose those edited pads*. For more, please see `Why do Parts in a PCB disappear when the PCB is updated from the schematic?` in: https://easyeda.com/andyfierman/Essential_checks_before_clicking_the_Convert_Project_to_PCB_Update_PCB_or_Import_Changes_buttons_-7d2c6484b0c74aea930b1acf6459cd39 * Setting: `Keep Island = No` removes *any* copper area that is not connected to the net to which the area has been assigned. The size of the unconnected area is irrelevant. The unconnected state of a copper area can arise because the clearances and proximity between tracks and pads around it prevents any copper being poured between then to connect a copper area and so it ends up as an unconnected island.

Is there a chance to see wich GND plane parts are not connected together?

If you toggle between Keep Island = Yes and No then you will see all the unconnected copper plane areas switch in and and out of view.