Random values in sp3 velocities

[JulieTls]

I've tested sp3 import. The function is efficient and really easy to use.
My problem is that my sp3 file does not contain velocity data (no line that begins with V), however georinex.load returns filled velocity data (that seems to closed to zero or random).
I would prefer to have Not A Number (NaN) velocity values when velocity data is missing. Or at least on indicator on the type of data (P or P+V) ?
Thanks in advance,
Julie