I just had a CA (Bureau of Collection Recovery) added onto EX and EQ this week

.
TC EX - Down 48
CCT EX - Down 63
FICO EX - Down 14
TC EQ - Down 0 (TC doesn't seem to update scores too often, maybe 2 times per month for myself)
CCT EQ - Down 16
FICO EQ - Down 18
As you can see, there is no clear pattern to the drop. Remember, each score formula (PLUS, Vantage, FICO, etc.) uses a different scale which impacts the change in addition to the content of the formula.
BTW, this is a DOFD of 4 yrs ago and my second CA. It is also my first added derog since starting this process a year ago.