A number of people have encountered similar scanning problems after upgrading to Catalina. Most of the scanner/printer vendors have been slow to respond with 64 bit software upgrades, although most eventually do. I would keep checking. In the meantime, you can try using Apple's Image Capture app to do scanning. It will not provide all the features you may be used to. Also, VueScan offers a full featured app that works with most scanners. You can download a free trial version to see if it works for you. If it does, there is a one time charge to use it. I bought it and I like it a lot.
VueScan Scanner Software for macOS Catalina, Windows 10, and Linux