I tried all ports (443,3333,4334)
PoolCheck from NiceHash side
Pool verification process is complete. Tested pool is incompatible!
Pool host solo.ckpool.org resolved to IP 45.59.68.74... OK
Connecting to Stratum proxy for region: USA... OK
Selected mining algorithm: SHA256... OK
Sending mining subscribe request... OK
Sending login information... OK
Mining subscribe request successfully completed... OK
Received mining set difficulty... OK
Received mining set difficulty... OK
Pool difficulty too low (provided=10000, minimum=500000)... Error