I agree with the theory about Steph and Josh being secretly separated. Her stories last night about her therapy sessions and how she's now at a place where she feels happy and doesn't need regular sessions. I feel like they were to do with the marriage breakdown and now she has accepted it.
She hardly posts him anymore.
She used to always post them having coffee in bed in the morning or one of them dancing in the bedroom or going out on dinner dates. Now the posts with him in it are centred on both of them doing an activity with Harvey. Her usual morning posts are her and Harvey alone. It may also explain Harvey's change in behaviour towards them as he has realised life has changed. She's poating more negative things about Harvey because she's now having to spend so much time alone with him without Josh there.
Or maybe I'm reading too much into it