E data connection only when roaming in Czechia

I have tried all 3 network operators in Czechia and they all only connect to data with an E (which I think is 2G) connection. All settings have been checked and phone restarted etc

Others using the same network have a 4G or 5G xonnection..and in other EU countries - for example Belgium - my phone connects with 4G or 5G. 

Smarty support say it must be the network carrier at fault, but it's the same on all 3 available networks at different locations, so I find that difficult to believe

Is there anyone else with current or recent experience of roaming in Czechia?