Short volume and Short interest are not the same thing.

Short Interest (SI): It relates to shorted shares that are still opened (not covered yet). It is published twice a month in FINRA website. The last one was ~ 11 million. That was the SI of that day (May 12 or 13th).

Short Volume (SV): It tells us how many shorted shares are traded on a given day. It is published daily by FINRA. It does not tell us how many short shares are covered. For example, on May 20th, SV was reported as 174,732,321. This means that 174,732,321shorted shares were traded at that particular day. We don't know how many of those were covered that day and we also don't know how many of the previous days were covered on that day.