Welcome back to the Wefugees Community and thank you for your question.
A "normal" Duldung would be issued according to section 60a of the German Residence Act and the Duldung for "persons whose identity is not varified" refers to section 60b of the residence law - often described as "Duldung light". The immigration office may want to issue that kind of worse Duldung if people don't present a passport, for instance. However, they should inform you as soon as they introduce the procedure of "downgrading" your Duldung. With receiving the Duldung light, people also need to face santions as considerable social money cuts, a work ban, or the prohibition to move freely to another place/region in Germany.
Another negative aspect is, that the time you are holding the "Duldung light" can actually not be counted for the minimum length of stay criteria (i.e. applying for residence permit according to section 25b).
In case the immigration office is introducing such a procedure or may have issued the Duldung according to 60b already, I would highly recommend you to get support by a lawyer or in a counselling office, for instance.
This brochure explains the details and gives further information (in German though).
I hope this helps and all the best,