Overriding to many of the following issues is the quality of the solution. If the camera is not well calibrated, or there are some issues with the orientation (position and angles) of the camera for each photo (perhaps due to Coded Target issues (were moved, not enough overlap), or SmartMatch issues (not enough overlap or texture-less surfaces), then the Bent Tubes may not form correctly and any number of the issues below can occur. The first item to check/fix with any Bent Tube issue then is to study the quality of the camera solution. Are the point residuals too high? Did some photographs not orient due to points being removed? Check for a good camera calibration and check for all camera stations being oriented correctly. Once you have a high-quality project, then these Bent Tube issues can remain: