Please read https://hampager.de/dokuwiki/doku.php?id=faq

Please specify which LED state do you see on the device from this list: https://manuals.sharkrf.com/openspot2/e ... l#page-top

- Make sure you use the Save button at the Wireless scan list to save the iPhone's Wi-Fi network to SSID #2 as it contains a special apostrophe character which you can't enter using your keyboard - Make sure you keep the iPhone's Wi-Fi hotspot settings page open while doing a wireless scan on the op...

The openSPOT4 has a proper dejitter buffer and works totally differently than MMDVM, so it's pointless to compare buffer lengths (looking at the MMDVM code we see that there is no dejitter buffer implementation - the MMDVM decides if there is packet loss if there were no packets received in the time...

GPS data embedded into the voice stream coming from the transceiver is transferred untouched to the server.

Have you tried contacting your MMDVM hotspot's support/manufacturer? Even if 76% of hotspots are MMDVM, there may be bugs in them, noting the fact that there are no problems on Thumb DV and Droidstar or other openSPOT devices. There are old issues with broken receive on MMDVM in the MMDVM Github rep...

Please upgrade the device firmware manually.
You can find the manual upgrade instructions in the user manual: https://manuals.sharkrf.com/openspot2/e ... e-firmware ("I want to manually upgrade the firmware" section)

Please make sure your openSPOT4 is running the latest beta firmware v21.

Please run DMR AutoCal, or manually adjust the RX offset on the Modem page in +-100Hz steps for the lowest BER. You can verify settings using the openSPOT4's built-in local echo service on DMR ID 9999.

Do a factory reset on the openSPOT4 by holding the Wi-Fi button for at least 30 seconds while the unit is powered on. If it does not help then use the recovery app. Download link is at the "The device does not turn on" section on the user manual's Troubleshooting page at https://manuals.sh...