I just updated Muse today 2/19, and all kinds of issues are happening. First is the asset warning that an image is being used larger than it's original size. I have at least 8 of these errors in my asset panel (referring to jpg or png files). However, they are exactly the same size on the Muse page as they we created. I used the "place" command to import the image files, scaled them to 100% (because they paste in at a much lower size- why? anyone?), and I have errors on half the images. For example, my Muse site is 1080p wide. I created a vector image in illustrator- exactly 1080p wide-, placed it in Muse, scaled to 100% and I get an error. Relink, nothing changes.
Also "preview page in browser" displays incorrectly and it was working yesterday. I made no changes in the site design that could account for this. Using Safari.
Purchased the Adobe approved Musegain.com widget Absolute Muse Gallery which is an Absolute Muse Nightmare. Seemed to be working begrudgingly yesterday on install, but has gotten out of control infuriating today. Anyone have any insight?
I haven't heard of any similar issue with the latest release. Some of your issues could have to do with third-party widget issues.
I would suggest getting in touch with Adobe Customer Support Contact us | Adobe for help. They should be able to collect your files and investigate the issue for you.