RN314 upgrade firmware to 6.4.0 Issues

It seems that the recent firware 6.4.0 has caused several different issues so far but I am yet to see a solution that resolves my issues on the forum.

I upgraded to 6.4.0 at around 2pm yesterday and it appeared to work correctly, no boot issues.

My NAS is set to turn off at 1am and come back on at 9am, which it did according to the emails it sent me.

At 9:15am it should perform a FTP backup of a website which it started to do then stopped and emailed me - "Backup Status: Fail: connection cannot be established. Check the connection and authentication, if required."

I logged in to the admin interface and tried to re-run the backup job which it started to do then stopped a few minutes in and kicked me back out of the admin interface.

I was then unable to login to admin with the admin progress bar timing out.

My PC could see the NAS in File Explorer but couldnt access the folders or files due to a 'network error'

The Readycloud app can see the NAS but wont access anything.

I force powered down the NAS and then turned it back on again and it booted back up.

I could then access the NAS as normal through any interface I used but then after a few minutes it went back to the same error as before and refused me access.

When I do have access to the NAS it seems to be running slowly.

It wont power down gracefully and it refuses to reboot (but it will boot from a force shutdown), it just sits on the 'see you soon' screen

Raidar is showing the NAS as Healthy and raidar will browse the folders and files when using the IP but it wont open admin.

I have no idea what to do next. I am out of support with Netgear.

Does anyone have any bright ideas on what I can try. I have around 7TB of data that will take several days/weeks to rebuild.