Open Neutral in Circuit - Need Help Troubleshooting
Check for a bad splice or connection in the neutral at the last good outlet
Between the outlet-tester results and the lack of power to the GFCI at the end of the chain, this is likely a bad splice or connection at the last good outlet's neutral.  Backstab-type connections on receptacles are commonly to blame for this; if you see any, converting them to side-screws is a better bet.