Created attachment 90107 [details] Open file in 4.0.6 and connectors are fine. Open in 4.1.2 they are reset to default Drawing block connectors that have the offsets manually adjusted do not open correctly in 4.1.2. Basically all the offsets get rest to default when opening.
That is a known problem and already fixed. It will be integrated in the next release. *** This bug has been marked as a duplicate of bug 70210 ***