DriveApp.searchFiles not giving all matching files - google-apps-script

Question

I am trying to create a Google Sheet where all instances of Sheets with the same string prefix in the title are gathered, in particular their file IDs. Out of 110 files with a perfect match, the output is only 24 files, always the same files. I am testing this to not actually alert clients in a different outputtest sheet, for which I have written the code underneath:
function onOpen(e) {
SpreadsheetApp.getUi()
.createMenu('testMenu')
.addItem('mainFunction', 'main')
.addToUi();
};
function main() {
var sheetName = 'Contacts';
var q = '(title contains "2022 Client Data ")'; //all titles start with this string
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var sheet = spreadsheet.getSheetByName(sheetName);
var data = sheet.getDataRange().getValues();
//loadSettings(spreadsheet, data);
var clientNames = getClientNames(data);
var clientFiles = getClientFiles(q);
//var eDict = matchClientWithFile(clientNames, clientFiles);
outputTest(spreadsheet, clientFiles);
};
function getClientFiles(q) {
var files = DriveApp.searchFiles(q);
var clientFiles = {};
while (files.hasNext()) {
var clientFile = files.next();
clientFiles[clientFile.getName()] = clientFile.getId();
};
return clientFiles;
};
function outputTest(spreadsheet, dict) {
var sheet = spreadsheet.getSheetByName('outputtest');
if (!sheet) {
var sheet = spreadsheet.insertSheet('outputtest');
}
for (const [key, value] of Object.entries(dict)) {
sheet.appendRow([key, value]);
};
};
The text in the q-string is the only requirement for a file match, as all file titles start with "2022 Client Data" which is really the only identifier. All files are stored in a shared directory.
I have looked up previous StackOverflow questions as well as documentation to see whether everything was in place, as well as making the q-string less specific and cleaning up the code, with the same result.
Drive searchbar with the type:spreadsheet title:"2022 client data" shows the amount of matches I should be getting in the outputtest sheet. I am hoping to put all 110 currently existing files together.
EDIT: when accessing it from a different google account in the shared Drive, the amount of files changes. It is highly likely this has to do with the DriveApp.searchFiles function only accessing the files that have been created by the account running the script. Is there a way to change this?