SignalTap reports invalid JTAG configuration

We are trying to SignalTap a Cyclone 10 device and are getting "invalid JTAG configuration" errors. This is the first time we have attempted SignalTap with the specific devices in this JTAG chain (CPU, FPGA, ETH PHYs (2)). Using the Quartus JTAG debugger, we can get the tool to see the four devices, but the PHYs are reported as unidentified. We know from the PHY BSDL files that no device ID is defined for these parts. We know the chain is essentially intact since the tool can identify the JTAG IDs of the first two parts in the chain, and this scan data propagates through the PHYs. Also, a third-party JTAG tool passes basic infrastructure tests on the full chain.

Is it possible that Quatus is getting tripped up due to the lack of JTAG IDs in the last two devices in the chain? Any other ideas? I should note that after the first quasi-successful Quartus JTAG scan where at least the four devices in the chain are acknowledged, subsequent scan result in no chain being recognized at all.

Thanks,
Greg