Using several templates, each on its own sheet in the same Spreadsheet, seems not possible.
When using a template this will create a new spreadsheet (eg Sheet1/Ods1).
In CALC it seems not possible to create/fill Sheet2 in Ods1 based on another (or the same) template, so Sheet2/Ods1. This will generate Sheet1/Ods2.
sorry, I'm not really sure what you are doing or what exactly you mean. Documents can be created from template documents, not sure what you mean about sheets and templates ( afaik a document can only be based off a single template ) Please can you give some exact steps about what you do, describe what results you see ( and what results you expect ) also attach any relevant sample documents and/or screenshots to help us understand your issue
*** This bug has been marked as a duplicate of bug 33341 ***
Created attachment 42373 [details]
email with extra info from reporter