Quectel MC20ECB audio record size

We are using MC20 ECB GSM module for our client project. I want to record four 30 second audio clip in UFS during call which will played back to user during call. I am using following command to record audio

AT+QAUDRD=1,“A.amr”,3
AT+QUADRD=0
Like this I want to record 4 clips with different names “A.amr”,“B.amr”,“C.amr”,“D.amr”. The problem I am facing is that I am able to record audio maximum file size only around 31000 bytes while UFS still has lot free space available.

AT+qflst

+QFLST: “A.amr”,23778
+QFLST: “b.amr”,5060
+QFLST: “c.amr”,2918

After this I am not able to record “D.amr” file. The module gives full disc error.

AT+QAUDRD=1,“d.amr”,3

+CME ERROR: 4305

While UFS still has lot for free space accoring to following AT command ouput.
AT+QFLDS=“UFS”

+QFLDS: 215040,315904
So this command shows that the module has 215040 bytes of free space available. Thus how can I record longer length auido when free space is available? Is there any limitation on audio recording size? How can I make use of free space available in UFS?

For the MC20 module, in order to leave space for flash, the recording function should have been deleted. Maybe the audio was not recorded successfully. Please check whether the previous recording can be played successfully.