temat Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable") w Orange Flex

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Tue, 10 Feb 2026 14:11:13 GMT

When calling in CZ through O2 op call drops just before ringing with "server unreachable", other side have missed call.

It happens quickly, recently, it started few weeks back

Mobile data works fine.

Able to connect only to O2 op, could use any of the 3 ops we have few months back

Airplane mode on/off, esim on/off does not work.

Online help does not know what to do.

Only short term help is to delete esim and download new one. (not really a solution)

O2 op is probably making problems, will be orange flex ever usable in CZ? Does it have a solution?

Thanks

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* I’ve clarified the thread title — Wiktor

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

Glut — Mon, 06 Oct 2025 07:03:59 GMT

@mdgarf do you have active roaming packet?

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

j131 — Mon, 06 Oct 2025 07:03:44 GMT

Flex should roam in EU without any problems. Something is not quite right here.

EU roaming calling problem CZ, O2 "server unreachable"

mdgarf — Sun, 05 Oct 2025 20:41:58 GMT

It did, not any more.

Problem is, like this it is not usable and not worth keeping...

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

ketrasaArtur — Mon, 06 Oct 2025 07:03:26 GMT

@mdgarf I suggest manually searching for an operator and, even if it's blocked, choosing one other than O2. Check the connection.

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Mon, 06 Oct 2025 07:02:33 GMT

We have 3. One has "denied" in name other will not connect only O2 connects.

It is new behaviour, i suspect that local ops are making problems...

Olny esim delete and install helps for short time...

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

tolek — Mon, 06 Oct 2025 08:33:23 GMT

@mdgarfnapisał(-a)
We have 3. One has "denied" in name other will not connect only O2 connects.

Doc in PL lang where Orange PL can use roaming:

Source

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

ketrasaArtur — Mon, 06 Oct 2025 08:51:36 GMT

@mdgarf I'd check with T-Mobile and Vodafone. Theoretically, you should be able to connect to any operator while roaming.

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Mon, 06 Oct 2025 09:08:54 GMT

was able, not any more.

upfront refusal...only O2 is able to connect

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Mon, 06 Oct 2025 15:54:22 GMT

@tolek napisał(-a)

Doc in PL lang where Orange PL can use roaming:

Source

that is not true or updated, unfortunately...

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

tolek — Mon, 06 Oct 2025 09:37:45 GMT

It looks like an IMS issue. Try temporarily disabling VoLTE in the settings and see if calls can be made. Of course, this isn't the final solution – call quality on 2G (if 3G is already disabled) will be worse than on LTE.

Is WiFi calling working properly?

Advanced steps: Download SIP IMS logs from Android for diagnostics. This might be helpful: https://nickvsnetworking.com/volte-ims-debugging-on-samsung-handsets-using-sysdump-samsung-ims-logger/, but you can also find other guides for your case.

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Mon, 06 Oct 2025 10:07:55 GMT

Wifi calling works

5G is not working

LTE works

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

ketrasaArtur — Mon, 06 Oct 2025 13:17:20 GMT

@mdgarf It's possible that Orange doesn't have a 5G roaming contract. So switch to LTE.

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

tolek — Mon, 06 Oct 2025 13:50:06 GMT

When you start a call, do you see the network switch from 5G to LTE? Or if the service sometimes works as you mentioned, is voice using 5G (VoNR)?

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Tue, 07 Oct 2025 09:17:17 GMT

did that, but it would be good to know when change is comming and support should know...

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

mdgarf — Fri, 10 Oct 2025 08:51:11 GMT

OK, I have overspoke.

Even switching LTE, 5G 3G will not help.

Orange flex is not usable/working in CR.

Orange Flex: EU roaming call drops on O2 Czechia ("server unreachable")

tolek — Fri, 10 Oct 2025 10:49:58 GMT

@mdgarfnapisał(-a)
Only short term help is to delete esim and download new one. (not really a solution)

This is the strangest thing because then we know that it works - the happy path exists.

Can you try with a physical SIM card, not an eSIM?

@mdgarfnapisał(-a)
Online help does not know what to do.

@mdgarfnapisał(-a)
Even switching LTE, 5G 3G will not help.
Orange flex is not usable/working in CR.

The first line of contact does the simplest things, such as restarting, replacing the e-SIM, resetting network settings, etc. Please let them know in the chat that you'd like to report the issue further, as you've already taken multiple actions (describe them) and the problem persists. In my opinion, this needs to be analyzed by someone at the next level of support. I've searched Google, but I've found similar threads that seem to revolve around the 2G/3G/4G switch, but we can't be 100% sure it's the same problem as yours.