I am a very experienced baker. I have over 50 years of experience with at least 4 electric ovens. Three years ago, I moved out west and bought a deluxe model LG oven. Since that time, I have had several failures with cakes that I have made many times over the years with no problem. This has also occurred with breads. I have baked pies and cookies with no problem in this oven. The cakes that I have had problems with are sour cream coffeecake and Jewish apple cake. The coffeecake fell apart after having baked past the alotted time. It also tested to be ready. The apple cake while holding together is heavy, wet and soggy. I have had breads fail to rise in this oven. I have used an oven thermometer which shows the correct temp when checked. I am beside myself to come up with an answer. I would hate to give up baking and cannot justify getting a new oven.
I note that you say you ‘moved out west’; I wonder if you have moved from a low to a high altitude location?
Most of the western United States (Alaska, Arizona, California, Colorado, Idaho, Montana, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming) are wholly or partly at high altitude.
Although many baking sites classify ‘high altitude’ as being over 3000 feet, the USDA site suggests that differences may be experienced with baking anywhere over 2000 feet.
What you describe for cakes, cookies and pastry is what many sites suggest is likely, cakes either crumbling apart after an extended baking time or failing to set at all. Low air pressure means liquids boil and evaporate at a lower temperature
Quicker evaporation also has several ramifications. It makes baked goods more prone to sticking. And sugar becomes more concentrated. Some cakes won't set. Or by the time they do set, they've become dry and crumbly.
However your description of bread matches less well, do you find the dough just never rises or might it be a case of it overproving and collapsing?