Cannot connect to certain host after switch to Mikrotik router

Hi,
I was a user of tp-link, switched to mikrotik due to freezes that tp-link was encountering. Everything works great, no freezes here, but… I’m unable to connect to at least one site.
My router is RB952Ui-5ac2nD. I updated soft to newest available - 6.40.3.

I tried this solution: http://forum.mikrotik.com/t/solved-strange-multi-isp-issue-with-ccr/112408/1
as well as the other found on forum with setting TTL and MSS.
None worked.

I think it might be related to the fact, that my ISP is having it’s own intra-net through which I go outside.

So my network looks like this:
ISP (cable modem) → Mikrotik → PCs over wifi

Tracerouting the site while being connected straight to modem gives:

$ traceroute allegro.pl
traceroute to allegro.pl (5.134.210.134), 30 hops max, 60 byte packets
 1  10.146.0.1 (10.146.0.1)  6.315 ms  6.306 ms  6.299 ms
 2  10.0.1.4 (10.0.1.4)  6.377 ms  6.376 ms  11.720 ms
 3  * * *
 4  89.228.6.5 (89.228.6.5)  27.030 ms  27.025 ms  27.089 ms
 5  89.228.6.6 (89.228.6.6)  26.867 ms  26.999 ms  26.862 ms
 6  89.228.6.1 (89.228.6.1)  26.987 ms  22.857 ms  22.848 ms
 7  host-89-228-40-171.dynamic.mm.pl (89.228.4.171)  22.842 ms  22.781 ms  22.820 ms
 8  atm.plix.pl (195.182.218.8)  32.600 ms  43.996 ms  43.987 ms
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  allegro.thinx.pl (212.91.1.34)  31.240 ms !X * *

While doing it via router (or from it)

$ traceroute allegro.pl
traceroute to allegro.pl (185.31.26.43), 30 hops max, 60 byte packets
 1  router (10.121.121.1)  1.117 ms  1.117 ms  1.107 ms
 2  10.146.0.1 (10.146.0.1)  8.344 ms  11.338 ms  15.972 ms
 3  10.0.1.4 (10.0.1.4)  45.455 ms  45.453 ms  45.445 ms
 4  * * *
 5  89.228.6.5 (89.228.6.5)  31.715 ms  32.008 ms  32.018 ms
 6  89.228.6.6 (89.228.6.6)  35.807 ms  26.013 ms  28.492 ms
 7  89.228.6.1 (89.228.6.1)  29.319 ms  29.285 ms  29.251 ms
 8  host-89-228-40-171.dynamic.mm.pl (89.228.4.171)  25.428 ms  23.571 ms  27.428 ms
 9  atm.plix.pl (195.182.218.8)  28.995 ms  24.643 ms  25.002 ms
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

First of all - different ip. But while I was trying to ping the site it either resolved the name to 185… or 5…, as far as I checked - both are valid.
And no - pings are not going, packets are being lost.

Mikrotik has tons of options so probably switching some of them should work, but I’m getting lost in it’s “pro” UI.

I’ve also set IP->Settings

accept redirects
accept source route

but it didn’t work either.

I’d say problem’s related to this inner network of ISP and two many hops to go through, but don’t know what to do about it (TTLs didn’t fix it).
Any idea? I’d be glad for some help. Thanks!