It might be an issue.
It is the
real channel number that determines what antenna is needed.
VHF-Low, real channels 2-6
VHF-High, real channels 7-13
UHF, real channels 14-51
The virtual channel number (like 5.1) is a holdover from the analog TV days to maintain the identity of the station, and is what the TV displays.
In your case WSB ABC is on real channel 39, virtual channel 2.1. Channel 39 is a UHF channel so you need a UHF antenna for it.
WXIA NBC is on real channel 10, virtual channel 11. Channel 10 is a VHF-High channel, so you need a VHF-High antenna for it.
Most indoor antennas are pretty good for UHF, not as good for VHF-High. That is because the elements for VHF-High need to be 3x as big as the elements for UHF.
I'm using a GE 34792 Attic antenna indoors with an RCA TVPRAMP1R preamp but my channels are stronger than your channels. Channel 13 is my weakest and it is VHF-High. The GE antenna only has a folded dipole for VHF-High; not much gain. It requires assembly, so it would be difficult to return it.
The Winegard HD7694P is only $15 more and it has much more gain for VHF-High and UHF. After you unfold it, it would also be hard to return.
My report:
I think it's worth trying an indoor antenna with a preamp if you have an east facing window without a metal screen or low-E glass, but you will probably need to put an antenna outside.
If you had to use the attic, you would need an antenna with more gain and a preamp. If the signal loss in the attic is great, even that might not work.
You must be prepared to experiment if you can't put an antenna outside.