It's complicated with the MSM IMO.
Like the deeply entrenched poster on forums such as Pie & Bovril, FF or the Huddleboard, political people tend only to focus on grievance against their own side, without realising that the opposition also have such grievances. This attitude is particular prevalent amongst Scottish Nationalists from what I can see.
In terms of newspapers, most in Scotland will have pro-Union editors, and why not? The middle/higher classes overwhelmingly voted No in 2014, and these will be the guys who own the papers. In saying that, they still largely allow pro-separatism views within their pages, and often the arguments are framed in a way which is favourable to separatism.
The BBC is supposed to be impartial but I think it has failed in this in recent years. Rather than this being because of any deliberate attempt to make it left leaning, I think it's happened naturally, given the views that are deemed acceptable in today's society. It has simply gone with the culture, and that's how it's ended up where it is now, with so many people going off the nut about the license fee. They are out of touch with normal people and it has become incredibly woke and left-wing, with conspiracy theories about gender pay gaps and systematic racism being aplenty. The fact that it's being changed to stop this, and a whole new network is being created due to the gap in the market, tells a story.
I really don't think it's anti-Scottish Nationalist though. Individual examples of alleged bias are given, which are valid, but you'll find other examples from the Unionists too. It's just that Nats shout the loudest and have a grievance culture so strong and huge that it consumes their every day life. Politics shows such as Question Time for example bend over backwards for the Nats.
The SNP will use intimidation to get their way IMO, and sadly it works.