Hello "HelloCo".
Congratulations that you, like many before and surely also after you, were able to dive into the world of half-truths.
If, as the "specialist company" apparently noted, the screed still contained a lot of moisture and is therefore moving, that can only cause shaking of the head. The installation company has the duty, among other things, to check the residual moisture in the screed as part of its inspection and duty of care before installing.
If they did not do this, they violated their duty of care and are liable for all damages directly related to this as well as consequential damages (e.g. compensation).
If it were really as claimed, the PVC planks would have detached more or less (e.g. in bubble form) from the subfloor.
You can check this yourself by running your fingernails over the plank surface.
If you do not hear any noticeable "chirping tones," the covering is still firmly fixed. Excessive residual moisture? To be excluded.
Especially since the carrier material is moisture-resistant so that it does not swell when moisture enters.
Now check the end joints with the same fingernail principle.
If you hear no chirping tone, the end joints are also firmly fixed.
Excessive residual moisture: also to be denied.
What has almost certainly happened here is that the delivery (planks) was stored in a cold car or warehouse before being carried into your house.
Without sufficient climate conditioning (at least 24 hours in the rooms where the covering is to be installed at the same temperature), the covering is subject to natural length expansion when it moves from a cold room into a warm one.
And if this expansion behavior is not waited for before installation with an 8mm thick system structure, well, then it simply expands after it has already been glued down.
And then there are such dimples. Or if the total area of 20 m², which the manufacturer has approved for full-surface bonding, is significantly exceeded.
"It will settle again, just ventilate well!"
Complete nonsense, this only serves to calm the builder in the hope they will get used to the appearance in the next few weeks.
A dimpled PVC covering as a module structure, as visible in the photos, remains as it is! No matter how well and how often you may ventilate.
Unfortunately.
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Regards: KlaRa