@Kevin_Z
Hi Kevin,
Thank you for your reply. I am not sure how to show the network diagram, but it looks something like that:

Pinging to World of Warcraft:
1)
Tracing route to 185.60.112.157 over a maximum of 30 hops
1 17 ms 89 ms 93 ms 192.168.xx.x
2 5 ms 5 ms 21 ms 37-157-xx-x.net1.bg [37.157.xx.x]
3 51 ms 6 ms 6 ms M240-37.net1.bg [37.157.xxx.xx]
4 6 ms 6 ms 4 ms D240-2.net1.bg [37.157.xxx.x]
5 8 ms 4 ms 5 ms te0-0-2-2.rcr11.b025634-0.sof02.atlas.cogentco.com [149.6.68.65]
6 9 ms 5 ms 5 ms be2057.ccr31.sof02.atlas.cogentco.com [130.117.2.57]
7 9 ms 11 ms 31 ms be3421.ccr51.beg03.atlas.cogentco.com [130.117.0.94]
8 23 ms 25 ms 58 ms be3464.ccr52.vie01.atlas.cogentco.com [154.54.59.189]
9 36 ms 43 ms 29 ms level3.vie01.atlas.cogentco.com [130.117.15.162]
10 43 ms 130 ms 41 ms ae-1-3104.edge7.Amsterdam1.Level3.net [4.69.162.177]
11 56 ms 51 ms 80 ms BLIZZARD-EN.edge7.Amsterdam1.Level3.net [212.72.41.90]
12 55 ms 60 ms 44 ms ae1-br02-eqam1.as57976.net [137.221.78.35]
13 72 ms 108 ms 193 ms 137.221.78.89
14 38 ms 56 ms 40 ms 137.221.66.47
15 95 ms 146 ms 165 ms 185.60.112.157
Trace complete.
2)
C:\Users\valen>tracert 185.60.112.158
Tracing route to 185.60.112.158 over a maximum of 30 hops
1 5 ms 4 ms 5 ms 192.168.xx.x
2 13 ms 4 ms 3 ms 37-157-176-1.net1.bg [37.157.xxx.x]
3 4 ms 3 ms 19 ms M240-37.net1.bg [37.157.xxx.xx]
4 4 ms 15 ms 7 ms D240-2.net1.bg [37.157.xxx.x]
5 10 ms 6 ms 6 ms te0-0-2-2.rcr11.b025634-0.sof02.atlas.cogentco.com [149.6.68.65]
6 8 ms 4 ms 5 ms be2057.ccr31.sof02.atlas.cogentco.com [130.117.2.57]
7 11 ms 14 ms 40 ms be3421.ccr51.beg03.atlas.cogentco.com [130.117.0.94]
8 39 ms 42 ms 24 ms be3464.ccr52.vie01.atlas.cogentco.com [154.54.59.189]
9 59 ms 30 ms 32 ms level3.vie01.atlas.cogentco.com [130.117.15.162]
10 134 ms 58 ms 44 ms ae-1-3104.edge7.Amsterdam1.Level3.net [4.69.162.177]
11 44 ms 45 ms 38 ms BLIZZARD-EN.edge7.Amsterdam1.Level3.net [212.72.41.90]
12 39 ms 46 ms 39 ms ae1-br01-eqam1.as57976.net [137.221.78.33]
13 37 ms 37 ms 47 ms et-0-0-35-pe02-eqam1.as57976.net [137.221.78.75]
14 51 ms 37 ms 40 ms 137.221.66.41
15 41 ms 39 ms 37 ms 185.60.112.158
Trace complete.
3)
Tracing route to 185.60.114.159 over a maximum of 30 hops
1 3 ms 3 ms 4 ms 192.168.xx.x
2 30 ms 5 ms 18 ms 37-157-176-1.net1.bg [37.157.xxx.x]
3 8 ms 7 ms 13 ms M240-37.net1.bg [37.157.xxx.xx]
4 15 ms 5 ms 6 ms T960-5.net1.bg [37.157.xxx.x]
5 8 ms 11 ms 5 ms T240-6.net1.bg [37.157.xxx.x]
6 13 ms 7 ms 36 ms sfia-b2-link.telia.net [213.248.99.169]
7 33 ms 62 ms 35 ms prag-bb1-link.telia.net [80.91.247.82]
8 37 ms 48 ms 53 ms ffm-bb1-link.telia.net [62.115.121.118]
9 48 ms 45 ms 45 ms prs-bb3-link.telia.net [62.115.123.13]
10 189 ms 44 ms 129 ms prs-b8-link.telia.net [62.115.138.133]
11 88 ms 86 ms 57 ms blizzard-ic-348624-prs-b8.c.telia.net [62.115.178.205]
12 157 ms 73 ms 55 ms ae1-br01-eqpa4.as57976.net [137.221.77.33]
13 42 ms 41 ms 42 ms be1-pe2-eqpa4.as57976.net [137.221.77.69]
14 43 ms 43 ms 54 ms 185.60.114.159
Trace complete.
Error is: blz51901016
No difference when using only the main deco.
An interesting find is after several tests - it works when I switch off 5Ghz wifi on the Deco. The problem is though, that there are lag spikes observed - from usual ping ~ 35-50ms it goes to >3000ms and followed by disconnects. With 5Ghz enabled, even with the additional extender, it is not working. Also, while on 5Ghz, when connecting and error message appears, I get disconnected from the wifi. On 2.4Ghz, again after a while it disconnects the laptop from the router.
Thanks!