SSDI does not take WC settlement money from you, but receiving WC will effect how much SSDI pays you.

In my case, I still receive WC payments , so my overall monthly SSDI check is not as high as it would be if I were not receiving WC

That part I am 100% sure about, the following is how I understand it based on what I've heard, but I may be off here (and the money amounts are random)

If you are getting a WC lump sum settlement, they need to write it up a certain way.....like when my WC suit is settled.....SSDI could drastically cut the amount they send if I get $24,000 from WC BUT if they write it up as the $24,000 is not an award but the balance of $1000 month for 2 years (24 months) to complete the max amount (7 year cap in my state) of WC money I could get, then SSDI doesn't change how much they send me now and in 2 years (when the WC money was due to end), my SSDI would go up to whatever my rate is supposed to be.