The appearance of the annotations or color coding is not correct in the drawing page for the model file.
Some pipes or junctions in my model are not visible, but they are shown in the flextable
There are a few things that you can try to resolve this issue.
First, go to View > Refresh Drawing. If that doesn't do anything, try going to Tools > Database Utilities > Synchronize Drawing.
If neither of these impacts the appearance of the annotations, close the program and browse to where the model files are saved. Here you will see a number of file types, including the .dwh file. This controls the appearance of the model on the workspace. If there is a corruption in this file it could make the appearance of the annotations incorrect.
With this in mind, close the program and then delete the .dwh file. Reopen the program and open the model file. When you compute the model, hopefully the appearance of the annotations is correct.
If that still doesn't help, close the model and browse to the model location once more. Copy just the .wtg and .wtg.sqlite files (for the Water products) or the .stsw and .stsw.sqlite files (for the Storm-Sewer products) and move then to a new folder location. Then open and compute the model again. Moving the files will disconnect the backup and report files from the main model files, and can sometimes help with unusual issues.