Agree 100% with ElizabethT172! We also have a newletter that we print for those without email and the printed version is just embarrassing to send to our members. There has to be a simple way to make the document adjustable. Also, is anyone else having issues with formatting areas in a newsletter? Like the box that pops up to adjust font and font options is behind something and you cannot even click on it. Also, spacing is set at 1.5 but when sent it is no longer at that setting. Program has become very glitchy and it didn't used to be... having a quality program that is user friendly should be priority. Wish they would listen to the feedback.
To address the line spacing issue, it sounds like you have a problematic text block from being too many copies of copies deep. Built-up junk coding from copied-copies can cause a lot of unusual and unwanted behavior, including reversions on text, image, and coloring formatting. Copying from an earlier or more direct source (likea master template) can assist with avoiding the junk coding build-up that can occur from copying copies-of-copies. That way each of your copies only comes from a direct source, rather than going through multiple reiterations. Otherwise your next best option would be to delete the specifically problematic blocks in each re-copy, and rebuild them from scratch. Making sure the text you're copying in from another source (if applicable) is fully purged of formatting will also help.
Some of the issues you're experiencing, such as the issue with the toolbar not showing or not being clickable, also sound very much connectivity-based. Whether it's an issue of a lot of content in your email causing increased bandwidth usage for autosave and displaying/editing, ad/pop-up blocker or browser extension interference, or a combination of several factors, it may be worth performing somebasic connectivity troubleshooting, or using Read More / redirect links in your email to reduce the amount of content and overall lag. Based on the length of your monthly newsletters, it does sound like reducing the content actually embedded in the email, that you're actively editing, would go a very long way towards improving your editing experience.