I recently flew out of US to get my H1B visa stamped and the departure location in my I-94 history says "unavailable". However the date associated with this departure record is correct and reflects the date on which I left the United States. Will this cause an issue when returning to the US?
I have departed the US 7 times this year, via multiple airports. Every single entry in my CBP history has the correct date for these entries, but all of the "Departure" entries have "Unknown" as the location. Even one of the Arrival entries has "Unknown" as the location.
This appears to have started this year as every one of the dozens of entries/exits in the past has a specific location.
Despite this I have had no issues re-entering the US after each trip. So to answer your question, no, this will not cause you any issues when re-entering - as long as the entry is there that's all that matters.
No. The only thing that matters is that your left the US.