In short this is the complete story:
-KSA supported the Military's Coup against Morsi with Billions of dollars that went to the military accounts as per the leaks.
-A soft coup happens in KSA and a new Gov takes power, this new gov is more interested in the Iran frontier than the interior frontier, Islamic revolutions happening due to Arab spring and gulf kingdoms getting overthrown, which is a narrative pushed (coincidentally) in Gulf countries by Countries such as Egypt.
-Egypt's economy crumbles and demand KSA to keep up with the old king's promises.
-KSA's economy is in no situation to keep the old promises especially with KSA prioritizing the war with the Houthis than the quelling of revolutions.
-An understanding might have happens between the two countries sometime in 2015, where Egyptians (as per leaks) are trying to please king Salman by offering the two islands (Tiran, sanafir) to KSA, in recognition of old contributions (30~40 Billion) and in return of new aid packages.
-Egyptian media starts advocating of Saudi ownership of the islands, the military starts a series of lectures proving the Saudi ownership of the islands and preparing the military for the islands transfer, and a new book even gets released propagating that perspective.
Such as this:
and this:
-Egyptian government starts arresting some Egyptians for protesting against that transfer.
-KSA accepts the offer and starts new aid packages like Cheap Oil and some other investments.
-Egypt is not pleased as it had expected KSA to give at least the 6Billion dollars demanded by the IMF to secure Egypt's 12Billion loan.
-KSA disregard those ambitions as unrealistic in current economical situation.
-Egypt start stalling transferring of the Islands to KSA, even though the president signed them off already without putting the resolution to vote in the parliament (which is illegal).
-The case starts dwelling in Egyptian courtrooms.
-The Egyptian government's lawyer provides the court some documents proving that the Islands are actually Egyptian "by mistake."
-Egypt votes for favor of Russia's resolution in the SC.
-KSA is shocked and stops all aid to Egypt including oil.
-A court annuls the Islands transfer.
-Egypt's economy gets worse.
-Egyptian media starts flipping on KSA.
-KSA liberal media (anti MB and Islamism) does not respond.
-KSA seems to have discovered that the long range missiles launched at KSA from Houthis are somehow linked to a Chinese deal made with Egypt.
-KSA starts talks with Djibouti for a new KSA military base.
-Egypt objects.
-KSA asks Egypt to evacuate from waters near Yemen suspecting foul play with the Houthis.
-Egypt refuses saying it's is essential to their national security.
-New GCC resolution condemning Egypt for mentioning Qatar's name in the Church bombing incident.
-Egyptian media up their Anti-KSA rhetoric to a new level, some would say to the point of no return.
Here an Egyptian newspaper calling King Salman the "His majesty the traitor"
-KSA sends a high level delegation to Ethiopia and visits the Renaissance dam and promise new investments in the RD.
-Egypt's president goes to Uganda in a sudden visit 1 day prior to scheduled visit, where two things happens:
A fight erupts between Egyptian presidential guards and the Ugandan placae guards due to their insistence of entering the presidential palace armed.
The Ugandan president promises Egypt with "fruits, fish, and meats" which caused A sisi to laugh nervously at that proclamation. which tells of an increasing economical situation.