Some help understanding which firmware should I use - NVR DS-7616NI-I2

[JLPicard]

Hikvision firmware portals are a bit confusing for me, so I need help.
I have some problem with my NVR so I hope a firmware upgrade can fix the issues but I don't understand which firmware is ok for me.
I have a DS-7616NI-I2 NVR, european version.
As far as I understand, there are two european firmware portals: Portal UK and Portal EU.

In Portal UK I found that this is the last version (V4.22.005 build191208):

DOWNLOAD EU PORTAL

www.hikvisioneurope.com

In Portal EU I found that this is the last version (V4.40.010 build200430):

HIKVISION UK PORTAL

www.hikvisioneurope.com

So my questions are:

1. Are both firmware good for my NVR?
2. Why are there different "last version" in the two portals?
3. Why my NVR in web gui "System/Maintenance/Online update section" tell me that my version (V4.21.008 build 190625) is the most updated one and that there's not any new release to download?
4. Which is the correct update procedure?
5. Will I lose all my settings? Can I backup and then restore them?

Thank you in advance for any help.

 

[alastairstevenson]

Are both firmware good for my NVR?

Very likely - they are official Hikvision stock releases.

Why are there different "last version" in the two portals?

There are many Hikvision websites that offer firmware downloads - and there is little consistency in them. They are clearly not centrally administered, so it's probably down to how ell the local admins look after them.

Why my NVR in web gui "System/Maintenance/Online update section" tell me that my version (V4.21.008 build 190625) is the most updated one and that there's not any new release to download?

It depends on how up to date the target resource is. I've never seen that update button do anything useful.

Which is the correct update procedure?

There are several ways to update. I use the web GUI Maintenance menu.

Will I lose all my settings? Can I backup and then restore them?

What's the current version of firmware?
You must be cautious if you are not already using a 4.x version.
There have been multiple posts of serious problems 'bricking' NVRs when going from the 3.4.x versions to the 4.x versions of firmware.
The symptoms suggest the configuration is being corrupted.

It's good practice to have saved configuration exports for both the NVR and attached cameras whenever you change any settings.

 

[JLPicard]

Alastairstevenson you have been very exhaustive, I appreciated very much!

What's the current version of firmware?
You must be cautious if you are not already using a 4.x version.
There have been multiple posts of serious problems 'bricking' NVRs when going from the 3.4.x versions to the 4.x versions of firmware.
The symptoms suggest the configuration is being corrupted.

It's good practice to have saved configuration exports for both the NVR and attached cameras whenever you change any settings.

Actual version is V4.21.008 build 190625.
I'm going to install the latest I found on EU portal (V4.40.010 build200430).
I will save configuration before upgrading.
Thank you again.

(Another strange thing I noticed is that my actual version is not in any of the EU repository but only in the US one but, as you said, there is little consistency in them.)