@christoff83 We are a major supplier of ATS 2/3/4 Pole ATs's in SA and I came across your interesting post regarding the non auto switching of the ATS you had. The reason how I came across your post was because I had a customer who also had this problem and had the same inverter as you did. In addition to this, we have had one other customer with the same inverter that also had the same problem. It appears that this ATS does NOT work with these inverters (our ATS's are slightly different). On further research, it seems that these inverters were design to work in an outdoor camping environment working from a car battery hence the inrush current issue.
We suggest and offer another solution that works perfectly.
Thank you once again.