IGMP Proxy work bad

RouterOS Forwarding Protocols
1

Hi. I speak in english very bad, but i hope that you will understand me.
I have mikrotik hap lite. I want connect internet and IPTV with help router. My provider give me 2 addresses: 1 for internet(192.168.50.50) and 1 for TV (10.10.50.50).
I try setup IPTV without Internet. If it will work good, later will connect internet.
I do next:

  1. Download multicast package.
  2. IP ether1 10.10.50.50
  3. bridge ip standart 192.168.88.1
  4. STB connected in 3 port with ip 192.168.88.10
  5. In IGMP Proxy I create 1 rule with interface ether1 and chekbox UPSTREAM. Also I create 2 rule with interface ether3 without chekbox upstream. (make quick live)
  6. in firewall i create MASQUERADE rule(out int. ether1)
  7. create route 0.0.0.0/0 gw 10.10.50.1 (gateway asked in provider)
    And TV WORK, but not all chanels. Part of channels work, other part of channels not work(there is no picture)
    I tryed do it with tp-link TL-WR740N. TP-LINK work without problems, mikrotik doesn’t want work good.

WHAT I DO WRONG?