Hi and thanks for your post. I am unable to reproduce the phenomena you describe that the checkbox does not remain checked. You might want to check if you run the latest version and/or close/open the GUI to see if the problem persists.
Let me explain how the research queue mechanism works;
Normal research based on the queue:
For picking research it will always research towards the first technology in the queue, which is either a prerequisite for that technology or that technology itself. You can see which technology is being researched towards by the green heartbeat & circular arrows symbol in front of it. If you look on the info page for example you will see that automobilism is the first queued technology and it is being researched to (it has the green symbol in front of it). There are also 5 prerequisite technologies to be researched before it, so it will be one of those technologies that is actively researched. The philosophy here is that you queue the technology you want in the order that you want it. Prerequisite technologies are picked at random, if you need a specific one of those to be researched as soon as possible you should queue it earlier.
Researching infinite technology:
If you queue an infinite technology and you want to continue subsequent levels, you should make sure the checkbox "re-queue infinite tech" is checked. The queueing mechanism works as described above, with the addition that if the checkbox is checked and the infinite tech at that level is researched then the next level of that technology is queued at the bottom. This will ensure that multiple infinite tech are cycled through equally. I do not have the intention to add more intelligence to this, because practically once you reach true megabase scale there will be only one technology that you will truly infinite research.
AI auto research:
This option only works if the queue is empty, as the name suggests it is an auto research mechanism. When the queue is empty, it will automatically research towards: Essential technology, technology with a trigger unlock, or any other technology - in this specific order. If there is then a technology available that requires spoilable science it will prioritize that technology over technology that does not require spoilable science.
