Hello @Rose_Reuben, welcome to the forum.
I can't answer all your questions, but I can try to clarfiy and point out some things and hope you will join the conservation.
Target
CryptPad is made for browsers, the code runs in your browser (Javascript + CSS + HTML), so the operating system does not matter (besides very special issues maybe). So usally if you encounter a problem with e.g. Chrome version "x.y" on Mac you should also encouter the same problem with Chrome "x.y" on Windows.
CryptPad was created with Desktops in mind, so at the moment the usability differs on mobile devices because of different screen sizes.
Therefore a problem may appear or disappear when you use another browser. If it does it's a bug and the CryptPad team needs this info (e.g. via forum) to fix the bug.
So changing the browser is not necessary for you and you should not, but it often helps if you temporarily try a CryptPad issue with another browser to be sure, that it's not a browser related bug.
Questions:
a) Which chrome version do you use?
Browser Extensions
Because CryptPad runs in your browser it can be affected by browser extensions. For example if it can't load some files / URLs, because hey are blocked by a ad blocker or anti virus. It's the same you will already know from other websites.
But none of your problems sounds liek a problem with an extension. I just wanted to explain to you the technical base, so can better understand the problems you may experience and experience at the moment.
Version
The code that runs in your browser is fetched from the server you use. So it's always up to date. You don't need to do updates and you can't do updates. You can see the used CryptPad version usally on the login screen in the lower left corner. Or when logged in theCryptPad menu in the upper right in the menu item "About CryptPad". At the moment it should be 2024.9.0 or 2024.9.1.
The server - to put it simple - only stores the files from your CryptPad [browser] client.
Since CryptPad is opensource there exist several public servers and one can also host a CryptPad server on its own.
Questions:
b) Which CryptPad version do you use? (which one is displayed)
c) Which CryptPad provider do you use? (cryptpad.fr?)
Applications
CryptPad is basically a framework to encrypt and decrypt data and to run several applicatiosn (in your browser). The CryptPad team developed the framework and integrated or developed the applicatiosn. If it is a "small" application like kanban board or markdown editor then it is created by the CryptPad team.
But the 3 "big" applications: spreadsheet, document and presentation are made by the OnlyOffice project. "Big" means very large code base and several years of development. The CryptPad team worked to integrate these applications (usally they don't run without a OnlyOffice server) but they did not create them.
I guess you will already know this: Since these projects are open source you can take the code for other open source applications. That way you can vastly increase development speed, you don't need to reinvent the wheel. The code / modules / apps you take are the so called "upstream" projects.
But this also means if one has a problem or bug in an upstream part the CryptPad team can't solve it, it needs to be reported and solved in the upstream project. (Comparison: If you build a new radio into your car you report problems to the radio manufacturer, not to the car producer.)
Disclaimer: CryptPad code also developed over 10 years and the code is not small, dead CryptPad team, don't be angry on me ;-)
Problem 1: spreadsheet
So your spreadsheet problem may not be solvable via forum / via CryptPad. I would need time to reprocude. But if you'd like to try, then please test if you exoerience the same problem with prue OnlyOffice. For example you can use the demo at: https://www.onlyoffice.com/de/see-it-in-action.aspx
Problem 2: drop down menu
This may be a CryptPad issue. It would help if you post a screenshot, so that we "talk the same language" and so that I can see if you're within the OnlyOffice part or within the CryptPad part. Then I woudl try to reproduce the problem.
Questions:
d) What input devicde do you use? A mouse, a touchpad or a touchscreen?
Conclusion
Please give feedback and I hope you answer my questions and follow my advices. I hope I could help you to narrow down some of your problems. I'm a user like you and not part of the CryptPad team. Since CryptPad is open source that's the so called community support.
Questions:
e) BTW, you mentioned you asked support. Which support in your case? Via the support menu item in CryptPad main menu?