Why pages load once
A few of the science tools pause to load the first time you open them. Here is what is happening, why it is worth it, and why it only happens once.
What you are seeing
When you open a heavy tool for the first time (e.g., the chemistry structure editor or the smart icon search in the figure composer), BeakerBot pours a beaker while a progress bar fills. That bar is honest. It tracks the real work happening in your browser and finishes exactly when that work is done, so it is never a fake spinner.
Why there is a wait at all
ResearchOS runs with no server and never uploads your data. That means the heavy machinery these tools rely on (a chemistry engine, a search model, a spreadsheet reader) has to run on your own computer instead of on someone else's cloud. The first time you open one of these tools, your browser downloads and starts that machinery. That is the wait.
It only happens once
After the first load, your browser caches the downloaded pieces. The next time you open the same tool, it is ready almost instantly. On repeat visits the loader can even estimate the time left from how long it took you last time, so you know what to expect.
If something goes wrong
If a load fails (e.g., you lost your connection partway through the first download), the loader shows a Try again button rather than leaving you stuck. Once the pieces are cached, a flaky connection no longer matters, because the work is already on your machine.