From everything you've described, my gut feel is there's still a problem with the fuel filter. Did you replace all the o-rings exactly as they were? I ask because mine had the same problem after renewing the filter. I'd not replaced the large ring correctly before fitting the orange clip.
You might try to measure the fuel pressure at the Schrader valve on the end of the fuel rail. Either a proper pressure gauge attachment or using a mechanical tyre gauge (not electrical). It must read 50psi or more when the starter is operated.
Related thread:
https://the75andztclub.co.uk/forum/s...d.php?t=251001
There may be more.
TC