Wood flooring needs to acclimatize to the environment for a few days before being installed (shrinks/swells with the moisture in the air).
Vinyl flooring are designed to latch together. Every board has to be completely seated and latched together. The only way to fix it now is to pick it all up and try again.
Did you install immediately as you took it from the shop/garage/storage/etc or did you leave it overnight to reach room temperature?
No I installed it right from the store, but I checked the instructions and it said that was ok.
Edit: this is the product I used Lanier Hickory 12-mil x 5-in W x 48-in L Waterproof Interlocking Luxury Vinyl Plank Flooring (18.35-sq ft/ Carton) https://www.lowes.com/pd/SMARTCORE-11-Piece-5-in-x-48-03-in-Lanier-Hickory-Luxury-Vinyl-Plank-Flooring/1000844538
It's not wood but vinyl.
Wood flooring needs to acclimatize to the environment for a few days before being installed (shrinks/swells with the moisture in the air).
Vinyl flooring are designed to latch together. Every board has to be completely seated and latched together. The only way to fix it now is to pick it all up and try again.