Add %%page%% to the title of the archive page using the snippet editor. This will add the page number removing the duplicate title tag issue. If you have a static page set for your blog then check Settings > Reading to see which page is the Posts page – usually it’s the page named news or blog.
For example:
My blog name %%page%%
on the second page of your blog archive becomes:
My blog name – Page 2 of 5