Text will only go top left document - not in text box

If you're finding your text jumping to the upper left of your document margins without creating a text frame, or as you describe create a smaller text frame, then find your text cursor jumping to the upper-left corner of your margins when you click your text tool into it, it's generally because when the document was first created the Primary Text Frame check box is selected.

De-selecting the check box before creating a document keeps InDesign from automatically creating a text frame for the Parent Pages of the document file. That automatic text frame is then transferred to every document page created in the file. 

This feature is handy when, say, laying out chapters of a book where you want to flow text in a single column across every page. But not so much when you want to put text frames in specific areas you want it within your document pages. Because if you miss the edges of your intended text frames with your Text tool, it will then place the cursor in the primary text frame behind your work.

Since that Primary Text Frame check box can be a "sticky" feature, meaning when you use it in one situation, the check box can remain that way for any subsequent document you create, I recommend for most all new documents you leave that box unchecked, and only select it for the situations where that feature would be useful to you.

I suspect when you go into the Document Setup dialog box (File>Document Setup... menu command) on your problem InDesign document files, you'll see that check box is selected. While it's technically feasible to turn off Primary Text Frame options on all your parent pages, and all the document pages that have been created based on them, it's more practical to avoid the situation altogether by keeping that option turned off except for the specific workflows where it's useful for you.

Hope this helps,

Randy

Can you provide a screen shot? Make sure frame edges and invisible characters are showing. Also, always provide versions numbers, OS, and OS version.

This sounds like the preferences got slightly corrupted at some point and is generally know to happen from time to time. 

Try resetting your preferences:

InDesign 19.3 and newer go to Preferences > General > and click on "Reset Preferences on Quit" and then quit and restart.

Or
Windows: Start InDesign, and then press Shift+Ctrl+Alt. Click Yes when asked if you want to delete preference files.
macOS: While pressing Shift+Option+Command+Control, start InDesign. Click Yes when asked if you want to delete preference files.
A dialog will appear asking to delete the InDesign Preferences, select 'Yes' on this dialog.

More in-depth cleanse of preferences

https://helpx.adobe.com/in/indesign/kb/indesign-preferences-support-file-locations.html

Let us know how you get on!