I’ve been trying to map an area all day with little success, this is due because the GPS signal becomes weak (maybe because it’s too close to the house?). So I go back to where it lost the signal and wait for a strong GPS signal. That said I was able to complete the map, however when I looked at it, it did not look accurate at all.
If you don’t think it is accurate, drive the yarbo to the perimeter of the map and see if in the app its location is accurate. If it isn’t, delete the area and start over. Go slow and maybe edge up your PPVS settings under settings, Yarbo Labs. Only go 10-20 ft more for mapping. This may help.
Solution 
Do what @bryan.wheeler said and you won’t have a problem. Don’t linger in the area with weak signal when mapping.
I found that “time of day” matters too for “better” GPS.
Avoid track slippage if possible especially if using PPVS.
I remapped like 6 times 2 or 3 times. Hahahaha. Don’t try to get it right the first time. Map it and then go watch it. Tweak it. Repeat.
Sound advice. It likely won’t be perfect the first time or twenty. 
(that’s an exaggeration.)
Hi there, you can try Bryan’s suggestions to see if that helps. And please keep us updated about the results — we will help you if you have any more issues.
I’ve had similar experience that there appears to be certain times of day, particularly in the evening, where GPS seems to get spotty and even downright non-functional.
I’m in Norrthern MI and 2 days in a row between 4-5pm is spotty as hell. It was so bad yesterday I opened a ticket and posted here about it. @balmerjd