"I already finished eating lunch" is rejected

As is 'I have already finished eating lunch'

Or even I already ate lunch.

"I already ate lunch" should be accepted. It means the same thing.

"I already finished lunch" should be accepted

"I've already eaten lunch", was rejected.

We is there no particle "le" required here?

"I already ate lunch" should be accepted. 吃 is "eat." Reported 4/30/18.

don't you need 了 ? 我已经吃完了午饭