I know this may well be a controversial topic, but here is my reasoning behind it:
The events in PROMETHEUS and from all that has transpired so far from ALIEN COVENANT are creating serious continuity issues regarding the events in ALIEN, namely the WY knowledge of the xenos existence prior to the Nostromo landing on LV-426...
First of all, there is no way the events on LV-223, including Shaw's beacon, later picked up by the Covenant crew, were not known by WY execs, which poses the obvious question: Why did WY wait that long to go to LV-426 after the events unfolding on LV-223, just on the next moon, where they could have easily picked up the beacon from the Derelict on the next moon, and get the xenos decades earlier with no fuss and no muss...? Fans have been defending that WY already knew of the existence of Xenos prior to ALIEN events, hence why the Nostromo went there... I disagree completely and the first two Alien movies showed it perfectly: if Ash reported to WY about the Xenos and was instructed to retrieve it even if it meant sacrificing the entire Nostromo crew, then why was the Derelict ship slipped outta remembrance for FIFTY SEVEN YEARS until Ripley's report made Burke order the colonists to go to the grid where Ridley said the Derelict was...? So, if WY had known all along of the existence of Xenos, why wait decades until a towing ship happened to pass by Zeta 2 Reticuli and then wait fifty seven years MORE, twenty of them with already colonists on the ground, to become interested in Xenos again...!?
And here we get to the prequels... How come the PROMETHEUS did not get the distress beacon from the moon right next to LV-223, the infamous LV-426 upon having reached the destination threshold no less...!? We already know that the Derelict was an escaping ship from the outbreak that had taken place 2000 years before on LV-223 and was landed on LV-426 upon realization by the SpaceJockey that he was infected... I am sure you noticed that not only the SpaceJockey had both hands on the controls even after the chest bursting, but also the eggs were not toppled over nor was there any physical indication of the ship being crashed... So, going back to the events in PROMETHEUS, it becomes clear that the PROMETHEUS lands next to to an arming and storage hangar base, with five or six hangars with same number of Juggernaut ships... First question that popped to mind was that this was not a testing facility as the captain said, because all we saw were storage rooms like the Engineer Head one and just corridors that eventually led to the Juggernaut ship... Also, this base was clearly away from any civilization, which meant that there was nothing to test the bioweapons at on this barren planet... Also, there is a lingering question that will affect the credibility of David's plan: so, the Engineers had planned to wipe Earth two thousand years before the outbreak on LV-223 and then gave up...?! Unless this was a faction within the military branch, it makes absolutely no sense why would they give up on their plans to wipe Earth for the next two thousand years... I mean, when was the Engineer on the cryotube expected to wake up..? There was a deleted scene where the Engineer clearly asked Weyland and the others what they were doing there, which clearly contradicts the paintings where the Engineers clearly left clues for the humans to get to that system... So, were the Engineers that came to Earth secretly telling the humans to go to that system to foil the plans of the faction that wanted to undo their creations...? Very fascinating stuff...
So, long story short, the events on the PROMETHEUS and ALIEN COVENANT clearly conflict with ALIEN and ALIENS to a point where the prequels actually NEGATE what went on in ALIEN and ALIENS, as the WY already had more than enough data to go there, to both moons, retrieve the canisters, and experiment on... Especially with Shaw's beacon and signing off at the end of PROMETHEUS... What do you guys think...? And try to keep it civil... We are all fans here... 😉👍🏻