It's probably down to long cables with the associated increase in crosstalk between adjacent (unscreened) wires.
A typical computer case has over 30cm (1ft) of cableform between the motherboard and the front panel USB ports. Sometimes even longer.
If you add another 30 to 50cm (1 to 1.5ft) of external cable to a portable hard disk or SSD, you've doubled the crosstalk and further degraded the digital waveforms with even more cable capacitance.
A point comes where the relatively "clean" square waves of the USB3 digital signal at the mptherboard are reduced to "sine" waves at the end of 60 to 100cm (2 to 3ft) of wire.
This doesn't affect low speed USB2 waveforms to anywhere near the same extent as much faster USB3 waveforms.
In theory you can transmit USB3 over much longer cables, but in practice, shorter = better.
As you've discovered, connecting your USB3 devices to the rear panel usually results in success. This is because you have reduced or entirely removed undesirable cable effects from the equation.
Although you cannot do much about the USB3 cable inside the computer up to the front panel, you can shorten portable HDD/SSD cables to the absolute minimum.
Most high quality USB-C portable SSDs come with very short cables, typically 20cm (8in) long. Low quality portable USB3 hard disk disk caddies come with thin spindly 0.5m (1.5ft) leads which should be consigned to the garbage bin.
I use 30cm Startech USB3 cables with a Kingston CF/SD/microSD card reader on my laptop to reduce data corruption.
If any of your external drive cables are more than 30cm (1ft) long, buy new shorter cables.
Another thing you can do on a Windows PC is dive into Device Manager (in Control Panel).
Locate Universal Serial Bus controllers.
Open each and every instance of USB Root Hub or Generic Root Hub and disable Windows Power Management.
You do not want Windows to power down your USB devices to save energy, especially during long file transfers.
In addition, I use FreeFileSync to copy files over USB3 links and then I perform a "byte-by-byte" comparison of files on the source and destination drives. You need to click the blue cogwheel next to Compare and select File Content from the menu.
This doubles the time to transfer files, but the complete file data comparison check gives confidence of success. It is not enough merely to check the filenames on the destination drive agree with those on the source drive. Invisible data corruption can occur.
https://freefilesync.org/