Is there a low spot on your main floor?
Is there a high spot pushing up on your main floor?
Sometimes poor drainage is self perpetuating, the mud under the floor slab retains moisture due to poor and or improper installation of weeping tile. The floor slab heaves up and cracks appear, the uplift is such that the underlying weeping tiles do not drain towards the sump pit as designed and so the end result is more standing water is soaked up by the clay, and so the clay expands as it retains more and more water. Worst case, the mud under the foundation pads where the teleposts are situated also raise and push the beam up thereby causing cracks to appear on the interior walls, and raising the main floor, and causing issues with flooring and impeding the proper opening and closing of doors. Other issues present but not immediately evident include fractured plumbing joints and fittings, steel is especially vulnerable as it is rigid as opposed to ABS which is semi-flexible.
The remedy is to remove the floor slab, and re-excavate the weeping tile, install a deeper perforated sump pit to gather water further out radially, and to return the floor to original elevations the sub-base must be excavated accordingly.
Sometimes the job calls for interior structural repairs such as the repair or replace sagging beams, support and remove failed foundation post pads, install modern posts by swapping out the old wood support beams.