That would indicate the cooler is doing it's thing. So why is the engine heating the oil so badly is the question
The large difference in temperature in vs temperature out could also be an indication of low flow across the cooler. Without knowing what is normal, it is difficult to troubleshoot from outside.
The engine's ability to heat the oil is finite unless you have a bearing beginning to fail.
If it was my aircraft, I think I'd be getting my hands dirty about now.