Actually I didn’t try the electronics prior to shielding. I went on the process to rebuild the guitar so I didn’t try it without shielding. But on the former version I had no issues and it was not shieldedPix of the bridge, etc. may help with diagnosis.
Did you have the bridge plate hum PRIOR to shielding? That may be key.
Could you have damaged any wiring when wrapping the bridge pickup with tape?