Bed level errors - Forum - Delft3D Flexible Mesh

I'm new to Delft 3D and i'm using it for my master thesis. I have a bed level file in the format of xyz and I can upload it to the program perfectly, I'm using flexible mesh in Delft 3D. my problem is after i upload my line file and grid, i go to bed level properties to set a specific range for the color scale, the range i'm using is from 0 to 40, however when i go to properties to do so, I find the range values are set from minimum value of -999 to a maximum value of -999, so i tick the box and try to change the values from the ones mentioned earlier to 0 and 40 however they don't change, so i try to upload my file and interpolate, the results are correct but on the color scale the range is still set from -999 to 40, this affects the display of my results, since all i get is one big area covered in the same color. I tried a lot of things but nothing worked.

I even closed the program and tried another grid that i created earlier and this time the values where set from 0 to 0 and i tried to change them and interpolate, I have no idea how to deal with this issue and would appreciate any insight or help given.
I forgot to add that as soon as i upload my file it shows that my entire mesh has a level of -999 which is not possible , also i don't know if that helps, but i'm trying to create a model for a flooding scenario and my levels in the file im trying to upload vary from 20 to 38 meters.