Formatting means boxes and type, not “exactly Word on Tuesday”
Cheap tools screenshot poorly or reflow. We paginate. If the source used a font nobody embedded, substitution is how letters look slightly different — not a conspiracy.
Embed fonts
Especially brand faces. Calibri is easy. Boutique display faces are not.
Text boxes and wrapping
Tight wraps already fight Word. They will fight PDF too. Simplify if a box overlaps a table.