Series 3 is not the same writer/producer as series 1 & 2.
The writer/producer, Emilia di Girolamo took this amazing series, smashed it on the ground and took a sheet on it, completely ruined it. She is lucky the actors are so amazing and pulled off the emotional aspects of her sheety writing.
Somehow a twenty something year old regular joe and a middle aged refugee living in a caravan is an expert hacker hacking into people's computers/accounts; a master kidnapper able to kidnap nearly twenty people; can make a complicated explosive device with remote detonation; and apparently also an animator able to make a whole animation sequence embedded with a secret message to tell the police what to do.
Watching this in 2021 and so glad series 3 writer/producer Emilia di Girolamo isn't terribly busy making TV shows because she is terrible at it!