Time Machine "Loading Backup" never finishes....

So I am moving to a new mac...

I created three backups and sold my old mac...

TimeMachine, Carbon Copy Cloner, and Resilio Sync backups.

I needed some room so I stupidly deleted the CCC backup thinking two others would be fine.

...then I checked my Resilio and the folder is magically empty...

Definitely did sync it, took all night two nights running, but gone now POOF!! ...

So I have TM left... 2.7TB of backups over the last 6 months should do it right?

Anyway, the new mac is here and I selected (from a clean install) to 'Transfer ... from TM Backup'.

It finds the backups I have from all my macs, but it sits and reports that they are 'loading'.

The continue button is grey, presumably until it finishes loading, which it has not done (over ethernet) in 6 hours now, while the fan runs hot...

On one of my other macs, I have selected to browse other backup disks - nil seen!

Both these macs are on the same network (same switch even).

The Backups are on a QNAP server, so I can see them, although without a mac to mount the sparsebundles they are just 2.7TB of garbage. So I mounted them via AFP on a thunderbolt network share from the QNAP.

This shows me many date folders, but every recent folder I look in seems pretty empty except for one about 6 months ago. So I figure TimeMachine hasn't actually worked for 6 months, although it has created empty folders just to wind me up about it...

Anyway, restoring the 6 month old backup would be something...

I can manually copy that off now I have found them!

• if AFP copy actually works correctly for such a big folder for once that is....

Anyway, I figured this was worth a chat... Any thoughts everyone?

Why have I got the most recent backup folders with nothing in them?

• Pretty sure I haven't been getting any problems with a full drive or anything, and no errors reported.

I am assuming these empty folders are as they seem - no magic hidden data I am missing?

• By size, they are empty except for the library folders...

I can't verify a TM backup except on the original machine can I?

Any ideas what I can do differently to avoid data loss next time?

- me thinks scrap TM and always keep CCC backups, but that's disappointing isn't it?...

Thanks all, Martyn