GPS dropouts are some Vodoo since iOS got this half-multi processing. Did you try placing the iPad at a different spot, or use some other nav software? Some never have this problem, some never get rid of it and some part is the fuselage, some is the software, some is the iOS (sub)version, some may even be the language you run the iOS (own experience with a FD VFR version 1.something, running the iPad at language English was fine, English UK a mess). In the end these device are non-certified helpers and you have to experiment a bit for success.
The typical reaction is purchasing an external GPS, which may solve the problem, but adds one more point of failure - the connection (no free lunch). In case the dropouts are caused by fuselage shadowing it helps definitely, because you can look for a good receiption location, and for some aircraft it is the only possibility. In case you run into tricky threading trouble inside the smartdevice it will not help (same is true in any, may it be Apple or other manufacturer - these are limited portable devices in the end).
In case you are US, I would not think further and get one of these external GPS-ADS-B-WX-TIS boxes, but more to get all the great additional functions provided by great and unique US infrastructure, not neccessarily for GPS stability. But I would also look into other nav software, as I am skeptical of Jeppesens FD VFR approach.