We have a PostgreSQL/PostGIS SDE enabled database, but lately there is a strange issue when adding layers from this database to ArcMap or ArcGIS Pro. We can connect to the database without any issues and see all layers present in it. We can drag any layer in ArcGIS, but the layer is not visible in the data/layout view. It is however visible in the Table of Contents without an exclamation mark. We can even look in the attribute table, no problems there. If I select rows, the contours of the selection are visible, but not the polygon itself. Non registered SDE tables from the same database do work, so I have a feeling there is something wrong with ArcSDE. All tables also work in QGIS.
Is there anything I can do? I could not find similar issues online. Maybe there is something corrupt in the SDE registration?
On the pictures above: left how it is now, right picture is how it should be.
EDIT: I am using ArcGIS Desktop 10.5 and ArcGIS Pro 2.1. Postgres is on version 9.4. It was working just fine before, but suddenly it has this strange bug.