My old S5 needs to be replaced soon.

Limited my choice to the Android one concept because no pre installed bloat ware or modified UI.

Three devices are in my interest:

 

Mi A3

Motorola One Vision

Nokia 6.2 Plus

 

All differ slightly in price but also then have more features such as RAM or display size.

 

Any recommendations?

The Nokia is not available yet, so if you want a new phone now your choice is down to Xiaomi and Motorola.

The price matches their specs, the Motorola costs more, but in general you get better specs (but a smaller battery)

Imho the specs of the Xiaomi are sufficient, the only downside is the 720p display

If i were to buy a new phone and wanted to decide between those, i would go to a store and check the display of the Xiaomi. If i would consider this to be ok for me i would buy the Xiaomi. If i should not be happy with the display i would take the Motorola.

If i were not happy with both of them i would wait a month or two and check the Nokia once it's available.

 

The Xiaomi MiA2 was a very popular and well received phone and there is a lot of disappointment in the Xiaomi fan pages with the dumbed down successor.   You can probably still find some MiA2's for reasonable prices.  This for instance

https://www.lazada.co.th/products/1-xiaomi-mi-a2-sd660ram4gbrom64gbglobal-versionandroid-one-i253248859-s390867053.html?gclid=CjwKCAjwqZPrBRBn

 

There is also the A2 Lite but the price seems similar for almost the same specs so don't know of any advantage.

FWIW, there is nothing really wrong with a 720P display.  On a 6" screen you'd really need sharp eyes to detect even the tiniest difference between that and an FHD.  More battery efficient as well.   It's one of those things that all the hype makes seem more significant than it really is.