Ercoupe 415C pilot reported airspace incursion when the ADS-B receiver lost GPS service and did not provide an airspace warning. Pilot exited airspace and continued the flight.

Narrative

This was the first flight after an extensive annual inspection that included the removal and replacement of a cylinder on the engine. The flight was to be short and local as a first shakedown flight to ensure everything was functioning as intended. Because of this I flew an abnormal pattern from normal; and gained additional altitude to give myself more options in the event of engine issues or failure. I was more fixated on my engine instruments than normal; and didn't realize I had accidentally climbed 500 feet into ZZZ1 class B airspace after departing to the North. My normal path of flight when traveling North is to head slightly East until clear of the class B shelf. I followed that without yet realizing I had entered the B airspace continuing North to stay in glide range of ZZZ2 in the event of an emergency. When I decided it was time to head back South to ZZZ; I noticed on EFB the airspace warning and realized what had happened on the way North.Obviously; I ensured I remained clear of the class B airspace while flying back to ZZZ.The other potential contributing factors are:1) I had not flown in four months while my plane was in annual.2) For some reason my ADSB lost GPS while I was gaining altitude above ZZZ before heading North. Because of this I didn't get the airspace warning like I received when turning to head South.