Mobile networks may use EVS (hidef), AWR-WB (G722.2 wideband) and AWR-NB (legacy narrowband) codecs. Whereas most sipX implementations rely on G711 PCMU in the US.
So the SBC you are using towards PSTN, either directly or from a PSTN connectivity provider, must correctly transcode those codecs to PCMU, including DTMF SDP parameters. And sometimes it is also necessary to strip or modify SDP parameters in the SBC to something the Freeswitch IVR accepts.
We have done a number of direct mobile network SBC integrations with sipX towards carrier grade SBCs that transcode the above mentioned EVS / AWR-* codecs towards PCMU and PCMA , also on the 24.01 CentOS7 branch, so if you use the built in sipX SBC it should handle DTMF correctly from cell networks.