The first-year mentor has stepped down as coach of the powerhouse club, despite being reappointed during last season's finals series.
Differing views — between Stanhope's committee and Aynsley — on new details of Aynsley's contract was the catalyst for the split.
The recent development leaves Stanhope on the hunt for its third coach in as many seasons.
Stanhope president Damien Miller revealed the events that transpired in the lead-up to Aynsley departing the Lions and thanked him for his contribution at the helm.
“After we reappointed Cobey in August, the club and committee sat down recently to discuss new details on his contract,” he said.
“A few things just didn't align (between the committee and Aynsley) and unfortunately we couldn't agree on a couple of things.
“Everyone (committee and Aynsley) involved is disappointed, but at the end of the day it was probably the right decision for both parties to have a fresh start.
“And we wish him good luck for what he does next and we thank him for his time at the club.”
Aynsley said the differing views between the two parties were the main reason for his departure and there was no bad blood between himself and the club.
“I walk away with no animosity towards the club, unfortunately we were just worlds apart (on the new contract),” he said.
“Stanhope will always be special to me, Damien provided me with the opportunity to develop and grow as a coach.
“We had a great season and I wish the club all the best for next year and beyond.”
Aynsley led the Lions to a semi-final encounter against Lancaster — following a memorable elimination final win against Murchison-Toolamba — but suffered a 50-point loss to the Wombats.
As his club begins its search for a new coach, Miller said it was an "exciting time" to be involved with the club as it enters its centenary year.
Stanhope's A-grade netball outfit capped a remarkable undefeated year with a resounding grand final win against Dookie United.
And the under-18s were one win away from a grand final appearance and multiple juniors enjoyed strong performances in the senior outfit throughout the season.
“We now begin the search for a new coach, which is obviously not ideal in the middle of November,” Miller said.
“But the club is coming off a very successful season in netball and football and as always, we will look to be up there again next season in what is our centenary year.
“We're all looking forward to what is going to be an exciting year ahead for the club.”