A long run of drain hose between the dishwasher and the garbage disposal can cause a siphoning problem with the drain water. The dishwasher drain pump is designed to pump the water a short distance to the sink drain or garbage disposal. The configuration for the drain hose is shown in the image below for a typical Bosch dishwasher. Make sure that you have a straight vertical rise in that hose as shown in the images below. Since you have a straight run of drain hose, you may need to increase the height of that anti-siphon drain hose elevation if possible. You may also consider having a plumber install a siphon break in that drain hose if necessary.
It sounds like this problem has been occurring ever since you installed the dishwasher. It is unlikely that you have a clog in the drain system. I don't recommend that you try to access components beyond what is recommended in the owner's manual while the dishwasher is still under warranty. If the above tips don't help, you may need to have the dishwasher checked under the warranty. Follow the directions in your owner's manual for arranging that warranty service.
If you need more help with this problem, reply with additional details and the full model number of your Bosch dishwasher.