Samsung why do you keep removing helpful functions with updates. Firstly for me you removed things from the heealth app which made me swap to fitbit. Now you have removed chat bubbles from text messages and WhatsApp 😡
Samsung cannot remove anything from other company's products. What you are experiencing is third party apps not being compatible with Android 11 so you will have to wait for them to update them.
Try the detailed pop up style, it works for me for text and WhatsApp and I have a pop up on the screen, but not so much of a 'bubble' as such, it's bigger and more detailed