It will be interesting get confirmation of whether the handheld shows different coordinates as you move around.
I can't see how it could and believe that the repeater could only relay the coordinates of its outdoor location, which makes me wonder...
Nothing beats first hand experience. However, I strongly suspect the VPS system is the one controlling your drone indoors in a well lit area. Try flying inside completely in the dark to really test the GPS ability to navigate without VPS. The GPS...
Eight seconds is too long an exposure to expect the drone to be able to manage.
Even at two seconds, I would shoot several times to have a better chance of having one good one to use.