The Kernel Panic log is showing a problem with the SSD as indicated by this portion of the log:
nvme: "Fatal error occurred.
You have the non-Touchbar model which has a removable SSD. There is actually a free SSD repair program available for a very small number of these 2017 non-Touchbar MBPros. However, the only way an AASP can do the free SSD repair on one of these laptops is if their Apple service portal tells them a laptop is eligible for the free repair. I have personally found lots of our organization's 2017 non-Touchbar MBPros have bad SSDs, but we have had to pay for their replacement since those laptops did not qualify for the free SSD repair program although I'm sure these SSDs have the same issue.
I am 99% sure the SSD is the source of your problems. Unfortunately I cannot say whether the replacement SSD that Apple installs will be any better since Apple doesn't provide any details about the original problem or whether they have updated the hardware on their SSDs. You may be paying for yet another potentially defective SSD.
I personally would be quite upset at Apple or the AASP for not looking at or properly interpreting the Kernel Panic logs which would have easily told them what the problem was. I would contact Apple corporate and let them know how Apple or the AASP has incorrectly diagnosed your laptop to see if they can do anything for you. I doubt they will refund the money you already paid, but perhaps they will offer you a Customer Satisfaction Code so the SSD can be replaced for free. You could also speak with the manager of the store/shop to see how they could correct their mistaken diagnosis (an Apple Store should be better able to make exceptions, but you never know).
Good luck and let us know how it goes.
