Replacement of front axel twice

[Alenorm54]

Greetings all
My son’s 2003 X5 3.0i E53 has oil leak 9 month ago I looked at it and found the leaks coming from the seal between the oil pan and the front differential shaft. Dropped the front end and installed all news shafts and seals and did the Oil pan gasket too. Soon after the leak came back same location I contacted the vendor thinking something to do with the shaft and in return they sent me two new shafts (L&R) with new seals.
I did not trust the seals so I got new from the dealer. Again took the front end down and replaced everything again new. Two month later he noticed oil leaks again but massive this time and he kept checking engine, transmission brake etc for any evidence of missing oil but found none
Got the car from him and took the shield down and found the leak coming from the same location for the third time.
I checked the seals they were installed correctly and had no Cracks or sign of tear Do you think I need to replace the oil pan now? Any input will be appreciated and god bless