Datatables PDO maximum parameter error

Hi there,
I am running a SSP datatables on a MS SQL database using a custom class as found here: https://pastebin.com/q8iJWkY8

However I've run into a bit of an issue with the search function. When I try to search anything I get the following error:
DataTables warning: table id=memListTable - An SQL error occurred: SQLSTATE[IMSSP]: Tried to bind parameter number 65536. SQL Server supports a maximum of 2100 parameters.

The table I am trying to search on hard about 50 tables and thousands of rows, but the searchable columns are only about 10 or so, which makes me wonder why it's trying to bind 65536 parameters. Does anyone have an idea about this?

Any help would be greatly appreciated, thanks!