omg
I missed this thread. I had the exact same problem with my FP5 at Orange.
After some hours of trial of error and research on random forums I finally found settings for an APN which works in all conditions, sending/receiving mms and internet data
Here they are:
Name: orange-ok (or whatever you want I guess)
APN: orange.fr
Proxy: Not set
Port: Not set
Username: orange
Password: orange
Server: Not set
MMSC: http://mms.orange.fr/
MMS proxy: 192.168.10.200
MMS port: 8080
MCC: 208
MNC: 01
Authentication type: PAP or CHAP
APN type: default,supl,mms,hipri,fota,cbs,xcap [note: this is probably a bit many, but I put them all - anyone recommends differently?]
APN protocol: IPv4/IPv6
APN roaming protocol: IPv4
Bearer: Unspecified
MVNO type: None
MVNO value: Not set
Tell me if that works for you, for me mostly any variation leads to non-functionning mms emission.
Note: I have an eSIM and I’m on Calyx OS