Professional cheating
For me the biggest change in dealing with the pandemic professionally was organized and professional cheating. Of course cheating is nothing new but when I first started in this businesses my impression was that a few bad apples cheated and I could usually detect it because some student had an incredibly silly incoherent answer that is copied word for word by a student sitting next to them.
Over the years it became clear that students could get their homework answered by finding solution keys or by question and answer sites and so I started making homework only worth a token amount of points.
But I honestly had been unaware of the truly professional cheating opportunities now available until online testing began during the pandemic without proctoring. I was also shocked by the percentage of students willing to cheat given the opportunity to do so. All my exam questions would appear and be answered during the exam on sites like Chegg, Course Hero and Slader. A student just has to send a photo of their exam question and they get a photo of a complete solution back in 5-40 minutes. While the solutions are not always correct they are semi-professional. Also I discovered students used group chats like Discord and Whatsapp to share their answers, either obtained from the above websites or via a divide and conquer scheme. In one of my exams a student I caught cheating informed me that 90% of my students were cheating on Discord often with fake names so they could not be identified. This matches 90% of students using an answer identical to Chegg using a different method than we did in class or in the book. Most students register for these sites with fake names and emails or use somebody else's account so even launching an investigation with the site is not very effective at catching people. On timed exams where students got the questions in random order and could not return to a question I found students took 50 minutes to answer the first question and once the solutions became available on Chegg answered the remaining questions in no time flat.
While in person exams will resolve some of this, I now will have to carefully check students do not have phones when they go for bathroom breaks or disallow them and I don't think I will give take-home exams again.