Same ID on multiple pages will not an issue. But same ID on the same page will be an issue.
https://forum.blocsapp.com/t/couldn-t-find-the-missing-bloc/10376
There was an issue back in v3 of Blocs, perhaps similar has re-surfaced in the app? Resurfacing bugs have happened from time to time throughout the years and Blocs versions. https://forum.blocsapp.com/t/my-blocs-went-missing-on-the-tree-panel/5415
Otherwise, since there has been no response here, you can always send the project directly to Blocs Support HQ to get resolved. With Blocs Standard you have “Basic Email Support” and with Blocs Plus you have “Priority Email Support”.