Direct Sample HF Signal Mirroring versus Upconverter HF Reception?

I'm wondering how common of a problem this is with Direct Sampling HF reception?

In the my screen video capture in the link below, I have two instances of SDR# running:

https://youtu.be/Cqutv8Hn3GQ

The top half shows SDR# running with an RTL-SDR using Direct Sampling for HF reception. The bottom half of the screen show SDR# running with an RTL-SDR + Upconverter for HF reception.

At 14.4MHz, I've been noticing signals on the left are being mirrored to the right, and vice versa. In comparison, the RTL-SDR + Upconverter instance shows where the actual originating signals are. These mirrored signals are very strong and it explains why I was picking up WWV at really odd frequencies. It's easy to rule that one out as an anomaly. But if I'm just manually scanning the frequencies, I can't tell if what I'm picking up is an actual originating signal or a mirrored signal unless I'm already familiar with the station and know that it definitely does not broadcast on the frequency or I'm picking up a transmission that is definitely in the wrong band (but in HF, that happens quite often anyway even for legitimate transmission). So, I can't really trust my logging with the Direct Sampling HF reception without doing some detective work. LOL. Was hoping the compactness of the unit would simplify things...well...I guess physically. But, this is an inconvenience I was not expecting. Anyone else noticing this?

submitted by /u/dhsc19
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