Reading your other thread, it appears you have a working VPN in the manner which you require.
As for speed .. there is really nothing we can do to help you.
A little ASCII art:
+------------------------------------+
| Streaming TV Service (eg: Netflix) | <-- Who knows how they stream ?
+------------------------------------+
|
| <-- The Wild internet, who knows what throttling goes on here ?
|
+----------------+
| NordVPN Server | <-- Who knows how they prioritise your stream ?
+----------------+
|
| <-- The Wild internet, who knows what throttling goes on here ?
|
+-----------------+
| Your ISP router | No matter what your ISP tells you, you never get exactly what you pay for [*1]
+-----------------+
|
| <-- Your physical network, "probably" nothing to worry about here.
|
+----------------------------+
| Your VPN client to NordVPN | You say this is underpowered maybe [*2]
+----------------------------+
|
| <-- Your physical network, "probably" nothing to worry about here.
|
+---------+
| Your TV |
+---------+
Notes:
- 1. A VPN cannot send as much data as your line speed because of the encryption overhead.
- 2. It may be under powered but it is probably sufficient to handle the data it does receive.
As you can see, there are huge parts of the diagram which you simply cannot influence and therefore cannot change. I guess you could pay for premium service from the TV Streaming service, NordVPN and your ISP and then, if it still does not work, you would have somebody to complain to .. but openvpn simply cannot help with those aspects.
