I experienced the same challenges with Outlook "not meshing well" with Zoom meeting invites, and while none of the links to Microsoft articles or recommended solutions posted here in the community resolved my issue, I've identified the solution for my challenges encountered. Though it involves multiple more clicks (to accept a Zoom meeting invite and get it imported into (saved to) an Outlook (New Outlook) calendar).
When sent an email with an invitation to register to attend a Zoom meeting, after registering to attend I immediately receive a follow-up email from the meeting organizer noting....Thank you for registering to attend.... with options to "Add to your Google Calendar," or "Add to your Outlook calendar." If selecting "Add to Outlook Calendar," you immediately observe a .ics file (the calendar meeting invite) is downloaded and appears in your "Downloads" file. To continue the process to add it to your Outlook calendar, you must click on the .ics file (appearing at top of your "Downloads" files), which results in a new Prompt box opening up - that prompts you to Drag & Drop or Browse (Navigate to) the file (.ics file) you want to open. Doing so will result in NO further progress/actions - unless/until you first complete the second action in the prompt box, which prompts you to "Select a Calendar" (while the label doesn't explain this, it means to "Select a Calendar" that you want to import the meeting invite (.ics file) to. The drop down options for names of calendars displayed didn't include my name, so I had to first step away from this prompt box and navigate in Outlook to the list of all my calendars (my own and those shared with me) to identify my own calendar name (In new Outlook, my own calendar is simply labeled "Calendar"). Once known, use the drop down arrow in the prompt box to select/choose the name of your calendar (or the calendar you want to save the meeting invite to). THEN, you can drag and drop the .ics file from downloads folder into the prompt box (or use the "Browse" button to navigate to the .ics file in the downloads folder, highlight it, then use "Open" button at bottom). Then must click on "Import" button at bottom of prompt box, and the .ics file (calendar meeting invite/hold) should indeed save to your Outlook calendar as expected. Though - in order to confirm it did save to your calendar it isn't immediately visible after selecting "import." (prompt box doesn't close and display the calendar). One must navigate to your Outlook calendar, navigate to that date, then can see the meeting invite/calendar hold has indeed saved to your calendar as expected.
Numerous more clicks are now involved after registering to attend a Zoom meeting, and receiving the email from the meeting organizer with the option to Add to Outlook calendar.