Problems getting mobile data in France with Dutch provider Simpel

I have the Dutch telecom provider Simpel. Mobile data in the Netherlands works fine. In the Netherlands, I use Simpel with mcc=“204” mnc=“16”. See here some previous reports by me:

Currently, I’m in France, but I can not get mobile data working.

Do you have any suggestions to determine what is causing this issue?

When I go to GNOME Settings > Mobile > Network, Automatic is enabled. I see only one network name below, which is greyed out and checked. The network is Orange F. But at other times, I saw another name: BYTEL. When I disable Automatic, Choose Network starts spinning. Many times I got a timeout, but now I’m repeating it to write this topic, all of a sudden I do get a list, with several names duplicated: SFR, Free (2x), 208 16, BYTEL (3x), Orange (2x), Orange F. Before this, I often got a timeout in getting the network list.

Now I have the question which of these I should select. Or should I stay at the Automatic selection? How does this Automatic selection work?

Do I have to make any changes to the serviceproviders.xml? For example, for Simpel it seems that I have to use (also abroad, I got an SMS with this) the Access Point:

Any hints and suggestions to get mobile data working, or to debug this issue are welcome.

OK, this is very strange. Now, just after writing the post above, and thus fiddling with the settings, mobile data works. The network is now Orange F. So, for sure getting on mobile data can get some improvements, also I’m happy to have mobile data again, but unfortunately, I do not know what the root cause of the issue is now.

I lost the connection with the Orange F network that worked. Now I am automatically connected to BYTEL again, where mobile data is not working. Just as described in the first post of this thread.

Because of the issue with the timeout, I cannot change the Network back to Orange F, and therefore have no mobile data again.

Is there a CLI command that I can use to change the Network?

I also reported the issue with the timeout when getting the list of Networks: Timeout when refreshing mobile network (#342) · Issues · Librem5 / OS-issues · GitLab