WizFi360 SPI communication - two sockets - heavy load


We are having a problem with WizFi360 SPI communication, that happens after a few minutes of heavy load communication using two sockets.

After a few minutes, the WizFi360 enters a mode where it seems to send incomplete responses to AT commands, or only sends the answers after it has reached a certain amount of data to send.

For example, if we send a single “AT\r\n” command, it does not answer immediately, but if we send another “AT\r\n” command, it will send both answers at once:




In another example, if we send a command with a sintax error followed by a correct “AT” command, it also only sends both answers only after the second “AT” command, but the answers seem to arrive on reversed order:



When sending comands that have longer answers (several lines), it seems to answer with incomplete responses.
For instance, “AT+CIPSTATUS” starts answering immediately, but does not send the final “OK”. The final “OK” is only received after sending the next command.

Sending an “AT+RST” command restores SPI communication back to normal.

Settings: SPI - 50MHz clock
Two sockets open:
1 UDP connectin
1 TCP port 80 (HTTP) server

During our stress test procedures, we are sending UDP requests from a remote PC every 20ms and http requests 10 times per second.
The problem happens randomly after a few minutes. After entering this mode, the problem persists until the wizfi360 is reset.

Do you have any idea of a workaround, or anything that we may be doing wrong to cause this problem ?

Thanks in advance