Until Opera 60.0.3255.27 the behavior was as expected: You "minimize" Opera with the red button and it will be (active) in the dock. Click the Opera-Icon in the dock again and it will open instantly a new window. That's what I want. With the latest Opera ..... .65 a click on the (active) Opera-Icon in the dock causes... nothing. The Opera app appears in the menu bar without a new window, you have to click inconvenient "Open a new window" or "Open a new tab" in the (context)- menu.

Normal when choosing, overlapping in Speed Dial, no matter if small or big

Sorry, this won't help you, but I never had this problem with Opera. My speed dial tiles are always in the same order I wanted and never shifted. It must be some preference that not works well.

Updated to the latest Opera build and noticed, that Opera will not restore to a window, when it was minimized with the red button (macOS 10.14.4).
That's annoying. I had to minimize it with the yellow button....
Anyone else?

Newest version Opera 60.....70. Still the same bugs.
BTW: Do Opera developers sometimes visit this forum?

Two? Even if one includes the number of unreported cases, the problem does not seem to be widespread. Here in a forum, people who have problems get in touch. Those who don't have any will hardly ever get in touch.
I'm just bothered by the thought that a bug that relatively few people have is stylized into a general problem that "must" affect all Opera users. So the statements and partly spiteful answers in this thread reach me.
There seems to be an Opera problem that does not affect all users and probably in connection with other system settings that you are probably not even aware of.
I know that this answer is not too helpful for this problem, but it had to be said.

If it were a pure Opera problem, most people would probably have the same problem you mentioned. But it doesn't seem so, otherwise your thread would probably "overflow”.
I don't doubt that you have a problem with Opera, but as I said before, it's probably not just Opera. Unfortunately I can't help you, because I can't reproduce your problem. It is not said that all extensions "work" identically in all browsers. The substructure might not be the same. For example, extensions from the Chrome Web store under Opera sometimes have limited functionality. This is also mentioned by Opera when you load an extension for Opera which is actually intended for Chrome.
By the way: Do you still have this bug with the latest Opera version 72.0.3815.200?

Please don't conclude from your problem to all Opera users: Here Opera (latest version) runs without problems, fast and smoothly. I don't think that Opera alone is the problem...

Simply open a desired page, copy the address, click on "+ Add..." on the speed dial page and paste the copied page. Done.

I strongly assume that "home page" means "speed dial". Probably you deactivated it yesterday by mistake. You can enable speed dial again in the settings. You might have to put them together again.

Here no problem to open your linked page. The graphics are visible and the map is zoomable. No pop-up window.
macOs Catalina 10.15.7, Opera 72.0.3815.148

I have never experienced anything like this before. How about a good adblocker...?

I don't know exactly what the problem is, but under "Opera" "Display" you have the item "Show sidebar". If activated, you have the narrow sidebar with vertical buttons, not activated the normal horizontal buttons (Opera 70.0.3728.106).

Unfortunately I can't say anything about it, because I had always deactivated DOH. But I suppose that this is a bug in the latest version or it " gets stuck " with other settings. I would wait for the next update. Can't take too long.

Why DOH at all? I deactivated DOH in the browser and set Cloudflare (1.1.1.1 etc.) directly in the router as DNS server. No problems (Opera 70).