"Connection closed by foreign host" instant error

Hi friends.

We have intermittent problems for connecting with services that are under your CDN. Usually identified for wordpress plugin/themes third services

telnet 104.31.73.220 443
Trying 104.31.73.220…
Connected to 104.31.73.220.
Escape character is ‘^]’.
Connection closed by foreign host.

The symptoms are that we cannot use the service because a connection reset is instantly obtained. The TCP trace identifies the [R]eset

16:30:00.341077 IP (tos 0x10, ttl 64, id 50694, offset 0, flags [DF], proto TCP (6), length 60)
185.195.X.X.42566 > 104.31.73.220.443: Flags [S], cksum 0xcdc5 (incorrect -> 0x745c), seq 2508303845, win 29200, options [mss 1460,sackOK,TS val 1018194915 ecr 0,nop,wscale 7], length 0

16:30:00.355391 IP (tos 0x0, ttl 59, id 0, offset 0, flags [DF], proto TCP (6), length 52)
104.31.73.220.443 > 185.195.X.X.42566: Flags [S.], cksum 0x78fd (correct), seq 2225584276, ack 2508303846, win 65535, options [mss 1400,nop,nop,sackOK,nop,wscale 10], length 0

16:30:00.355454 IP (tos 0x10, ttl 64, id 50695, offset 0, flags [DF], proto TCP (6), length 40)
185.195.X.X.42566 > 104.31.73.220.443: Flags [.], cksum 0xcdb1 (incorrect -> 0xb8b1), seq 1, ack 1, win 229, length 0

16:30:00.379496 IP (tos 0x10, ttl 59, id 0, offset 0, flags [DF], proto TCP (6), length 40)
104.31.73.220.443 > 185.195.X.X.42566: Flags [R], cksum 0xfd0a (correct), seq 2225584277, win 0, length 0

This occurs from several computers within the same network range (/22). From other ranges we do not have this problem and the telnet is correct:

telnet 104.31.72.220 443
Trying 104.31.72.220…
Connected to 104.31.72.220.
Escape character is ‘^]’.

It seems some kind of restriction for traffic from our network. Can help us?

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