Seems you have a network issue.
please try to solve that first, it will also solve the random restarts:
# volumio endpointstest ---------------
TESTING REMOTE ENDPOINTS
https://google.com, 606 ms: FAILED
https://www.googleapis.com, 573 ms: FAILED
https://securetoken.googleapis.com, 550 ms: FAILED
https://myvolumio.firebaseio.com, 601 ms: FAILED
https://functions.volumio.cloud, 937 ms: FAILED
https://oauth-performer.dfs.volumio.org, 841 ms: FAILED
https://browsing-performer.dfs.volumio.org, 1054 ms: OK
http://cddb.volumio.org, 1670 ms: OK
https://functions.volumio.cloud, 947 ms: FAILED
http://pushupdates.volumio.org, 896 ms: OK
http://plugins.volumio.org, 1267 ms: FAILED
https://database.volumio.cloud, 897 ms: OK
https://radio-directory.firebaseapp.com, 763 ms: FAILED
----------
WARNING!!! Some remote endpoints cannot be reached!
Failing endpoints:
https://google.com, 763 ms
https://www.googleapis.com, 763 ms
https://securetoken.googleapis.com, 763 ms
https://myvolumio.firebaseio.com, 763 ms
https://functions.volumio.cloud, 763 ms
https://oauth-performer.dfs.volumio.org, 763 ms
https://functions.volumio.cloud, 763 ms
http://plugins.volumio.org, 763 ms
https://radio-directory.firebaseapp.com, 763 ms
----------
Dec 04 19:50:29 volumio dhcpcd[1516]: wlan0: connected to Access Point `'
Dec 04 19:50:29 volumio dhcpcd[1516]: no interfaces have a carrier
Dec 04 19:50:29 volumio dhcpcd[1516]: forked to background, child pid 1551
Dec 04 19:50:29 volumio dhcpcd[1551]: eth0: waiting for carrier
Dec 04 19:50:29 volumio dhcpcd[1551]: wlan0: waiting for carrier
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Dec 04 19:51:21 volumio volumio[773]: info: Retrying Login Due to Network Error
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Dec 04 19:51:21 volumio volumio[773]: info: Retrying Login Due to Network Error
Dec 04 19:51:21 volumio volumio[773]: info: MyVolumio login type: Token
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Dec 04 19:51:21 volumio volumio[773]: info: Retrying Login Due to Network Error
Dec 04 19:51:21 volumio volumio[773]: info: MyVolumio login type: Token
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Dec 04 19:51:21 volumio volumio[773]: info: Retrying Login Due to Network Error
Dec 04 19:51:21 volumio volumio[773]: info: MyVolumio login type: Token
Dec 04 19:51:21 volumio volumio[773]: info: MyVolumio login type: Token
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Dec 04 19:51:21 volumio volumio[773]: info: Retrying Login Due to Network Error
Dec 04 19:51:21 volumio volumio[773]: error: MyVolumio got a network error: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
Please post a screenshot of your network setup in volumio