Cannot complete downloads without error even after Nintendo repair

When I start a download of any digital game, or a patch for a digital/physical game, throughout the download I get error code 2137-8056 once or twice, but can still continue the download. When I continue it, it’ll get to 99% and then give me error 2005-0140, where the download cancels itself. I went through all of Nintendo’s troubleshooting steps and eventually decided to send the console to Nintendo’s repair service. They returned it to me unrepaired citing the SD card as the problem (probably since 2005-0140 is an SD error), but whether I have an SD card in or not, I still get the errors. I also have a secondary switch that has worked fine throughout this entire process, so I’m positive it’s not a network issue.