This post on AVC describes a common situation: technical problems when setting up a presentation. Different computers and different screens (dimensions, operating systems, resolutions, cables, plugs) make it unpredictable what happens when you connect the 2.
This a particular problem in marathon meetings, where a large number of presenters show up one after the other. It is a time waste for the audience and a concentration breaker for the presenter.
The solution in the post was an interesting one: use Zoom (or another web conferencing service) locally (i.e., standing in the same room). This eliminates the need for hardware connections and allows presenters to line up, solve any technical issues before they are due on stage.
In the absence of such a solution, my recommendation would be to always carry a USB stick with your deck around (in PowerPoint and PDF), just in case. Ultimately portable projectors will be compact and capable enough that everyone who has a high-stakes presentation to pitch will carry one around.