Yes, the mail system is currently hit or miss, luckily for you, the seller in France was honest enough to not just keep your money. I have had several packages make a quick transit and others going to the same country take 6-8 weeks. I currently have a Paypal claim against me from a guy in Spain. Tracking shows his coin has been in his country for over a month, but he filed a claim against me anyway. I have been debating about not even shipping out of the US until covid restrictions are lifted; but this might be the new normal for a while. Thankfully, most people understand the situation. I also often use USPS express post for packages over a certain amount (200ish), but even that has been delayed a bit; but is still usually much faster than regular USPS.
I even shipped a large order to China and was dreading the "slow boat to China" but I mailed them USPS priority express and they arrived in just about a week.
I also have a coin on the slow boat from Germany. This Constantius II was shipped four weeks ago and is still in transit. Interestingly, I bought another coin from the same seller a week later and got it last week, so only about two weeks for that one with the exact same shipping.