SOLUTION tested with SPH 4600 (built 2022)
connect the bat terminals on the lower right edge of the inverter
This will make the SPH 4600 switch its operating mode into a straight grid tied inverter as you know it from the growatt mic / min / mod series.
The 2 paragraph describes the solution where other british / americans hat told me that "float" in this case would not mean to connect or bridge the 2 bat terminals of the inverter.
And in the german manual it says "Bat Klemmen verbinden" which means: connect the Bat terminals !
You can ignore all the other sentences and paragraphs cause just this 1 or 2 lines are describing the solution.
And then the inverter will start to produce energy which can be viewed in the growatt cloud app and via browser.
Attention: it calls the production self consumption which does not mean the selfconsumption of the inverter but your the energy used in your home.
No other changes needed, just that.
And to make things even more clear:
in the display there is the inverter in the middle and the electricity pole right to it. If you might think as we that the arrows between both of these are missing then you are as wrong as we cause the arrows only show up if you measure the energy by using the clamp meter or 1 or 3 phase energy meter when it can detect the amount of energy you are feeding into the grid or from the grid.
As long as you see an electricity pole you can be sure that the grid is there, available.
And your selfconsumption without a battery will be represented by the bulb as the load the inverter is supplying.
Mystery solved after 21 months cause my first sph series did not produce energy and had been shipped back, got my money and then went ahead without an SPH till I got one last autumn and started again. Even though I achieved that this weekend it will be not that usefull cause the battery is coming and then I have to use this as a Hybrid. 21 months more or less lost.