My experience was different. After my Appareo ESGi was installed a couple of weeks ago, I flew the entire recommended flight test protocol (over an hour) in Class E airspace, below 10,000', about 40 miles north of here near Kelso WA, away from the heavy traffic in the Portland area.
The GAIRS Report (attached) came back as a fail -- the equipment passed the performance checks and the flight "met ADS-B Out rule requirements," but "The Performance Monitor could NOT validate that the flight operation consisted of at least 30 minutes in the airspace defined in 14 CFR 91.225. Please ensure the flight meets Program requirements for required flight time in the required airspace."
So I went back up the next day and just did lazy circles for half an hour in Class E airspace above the Portland Class C ceiling, and within the lateral limits of the Class C. Portland Approach was cooperative (and maybe a little bemused) with flight following for this exercise. The GAIRS Report this time came back all green.
Were you at least 30 minutes in the Mode C veil, or above or below a Class B or C? KLVK is within the veil, so just your time in 91.225 airspace leaving and returning may have been enough to satisfy the requirement. In my unsuccessful flight, the report said I was 11 minutes in 91.225 airspace. That must have been the time I was below the floor of Portland's Class C (technically not 91.225 airspace, but within lateral limits) departing and returning to my home field.