Why are customers experiencing shipping errors at checkout?

Yes I have also had this same exact issue. I did not receive any prior warning email as described below either. I used shipstation and the other thing I have noticed is when viewing which Shopify plan I am on, it now says the Shopify plan I am on is no longer available so if I make changes I cannot get the same plan. I had gotten on a plan that I had an add on amount to be able to use shipstation rather than upgrading to a much more expensive plan to use shipstation. So I have been wondering if this is part of the problem? I had tried to connect with Shopify through their chat and at first it said my wait was 40 minutes, then dropped down to 35, then 30, then 20, 10 , 5 and down to 1 minute wait…. it stayed on the 1 minute for an hour and a half. So in total I waited over 2 hrs and never could get in contact with help. I have had customers trying to place orders for Valentine’s Day gifts and unable. So frustrating and I thought Shopify had better customer service with my previous experience, but now I can’t even get ahold of anyone to figure this out. Shipstation actually has great support and they had me do a re-connect of the integration, but that did not solve this. Unfortunately it seems to be on Shopify’s end and here I am well past when they said it would be fixed. I have searched and searched my email for these emails about this and cannot find one. If anyone has a date they were sent out and a copy I would appreciate it! I have a job in addition to running my little business, so sitting on hold for hours before going off to work the night shift is really stressful…. Especially when you can’t get ahold of anyone to figure it out.. I’m losing sales, being made to seem very unprofessional and unreliable to my customers on account of Shopify’s lack of support and availability. I don’t even know how to proceed moving forward with this…