You're wasting your time expecting the TV to have a full programme guide (EPG) for the satellite channels unless it is branded with Freesat logo. I have an old (2008) Sony TV with a sat tuner and Freesat branded, so I do get a 7 day EPG, but it's a pain to use the built-in features and it's slow to switch between terrestrial and satellite (as you have found with the newer model).
Keep your combo box as @cactikid suggests and you will be better off for EPG and stable recording. Glad you (and the sat installer) finally resolved the issues!