Size of Mapview in Basic UI & zoom in automaticaly

openHAB version: 2.5.0.M3

I have placed a Mapview with Location item in my default.sitemap and the location of my Automower is displayed in Openstreetmap:

Text label="Automower" icon="sheep" {
  Frame label="Automower" {
    .
    Mapview item=mowerLocation height=5 icon="sheep"
    }
}

Whatever value I assign to height the map’s height does not change. The original height is to smal, what can I do to increase the height of the map?

Is it possible to zoom in to the map to highest possible step automaticaly? On each refresh the map goes back to standard, I have to zoom in again after.

regards
Werner

Amendment: On my smartphone running Android 8 I do not have any opportunity to zoom in to the map …

Werner