It's difficult to interpret the formula without seeing the parts of the table referenced. The highlighting of cells in the large table does not appear to match the highlighting in the formula.

Syntax for COUNTIFS:
COUNTIFS(test-values, condition, test-values…, condition…)
COUNTIFS is generally placed in a single cell if it is doing a count of items fitting a single set of conditions.
It is filled down a column if counts of several similar sets are being done. in this case, for example if you were doing counts for five different vssid codes, you might list the codes in five rows of a single column and use a relative reference to the cell in that column on the same row as the formula as the condition for one of the test-values, condition pairs. The formula would then be entered into the row containing the first code, then filled down four rows to create one copy referencing each of the codes.
Your formula has two test-values, condition pairs:
- vssid, vssid lbleakly2
- T, T114 < DATE(Table 2::$B$@,Table 2::$C$2, Table 2::$D$2)
See the comments above regarding the first pair.
The second pair has a couple of errors.
COUNTIFS looks at each of the test-values in column T and compares that value with the value constructed by DATE from the contents of cells B2,C2 and D2 on Table 2. The reference to cell T114 is not needed and should be removed.
The expression of the condition must be presented as text, but within that text, numbers needs to see any cell references as cell references, not as a text string. That' a tough concept to catch on to if you're not making frequent use of it, so it's not surprising when errors occur.
The values in column T must be Date&Time values, not text. If the alignment setting on that column is Automatic, Numbers will align numbers and number-like values (including Date&Time values) to the right edge of the cell, and will align text values to the left. The left alignment of values in column T means either you have set the alignment to Left, or the values in those cells are text, not dates, and cannot be compared with the Date&Time value constructed by the Date function.
Corrected version of this pair: T, "<"&DATE(Table 2::$B$@,Table 2::$C$2, Table 2::$D$2)
Here's an example using separate tables to record the data (Table 1), do the counts (Table 2) and construct the threshold date (Table 3)
Formula list below.

Table 1: Data only. no formulas.
Table 2: Two formulas
A2: =Table 3::A2
Copies the date from Table 3.
C2: =COUNTIFS(Table 1::$A,B,Table 1::$B,"<"&A$2)
Does the count.
Fill down to C5
Table 3: =DATE(A3,A4,A5)
Constructs the Date&Time value.
(Same as your formula, modified for a vertical list of yyyy, m, d)
Regards,
Barry