My mistake, I didn't realize that you weren't using the SMD board. I don't have any experience with the non-SMD version, but the symptoms sounded very similar to what I worked through with the SMD version. The other user is correct that the exact issues that I had with the SMD board do not apply...
This really sounds like the issues that I just worked through. Check out the issue I opened on the cherryphilip iSpindel-PCB repository: https://github.com/cherryphilip74/iSpindel-PCB/issues/19
I recently built a batch of iSpindels using the CherryPhilips version and found a couple of issues and workarounds.
(I ordered my PCBs using the files from commit 043505c on Dec 15, 2019)
Here is a link to Issue that I opened on GitHub that contains info about the two problems and the...