Multiple cars missing from Singleplayer Garage but available in Multiplayer

I am facing this issue where some of my cars (Around 4) have suddenly gone missing from my garage in Singleplayer. I cannot find them or use them anymore. They include cars that I have used for a long time and completed multiple singleplayer missions with. These include cars that you get from progressing the game itself (Subaru WRX, Audi S5, etc) and cars that I have bought myself. However, these cars do show up when I go to Multiplayer Speedlist and are available for me to use. I contacted EA support but they were unable to help and suggested I post in the forums. This first happened with one car in January 2018, and I disregarded the issue and bought another one like it. However, last month I started the game after not playing it for a while and multiple cars were missing. Please advise.