Mender 2.4.0 to 2.6.0 upgrade loses devices

I went ahead this weekend to update our 2.4.0 mender server to 2.6.0.

All seemed to have worked well, except that, out of the 60+ devices, only 10-15 show up after the upgrade.
Is there something that needs refreshing? Am I missing steps in the documentation?

Any help is greatly appreciated!

With kind regards,
Matthijs ter Woord

I should have done some more googling.

Following post contains some exta steps that might be needed when going from 2.4 to 2.5. It also fixes my problems:

@mterwoord correct, upgrading from 2.4 to any later version requires a full resync of the deviceauth and inventory services.