multiple '//' and more in URLs

These are probabling templating errors (?PHP?). Pages will fail.
[ complaints URL ] https://www.lebara.co.uk//en/complaint-code.html
fails with the extra '//' (without even a 404 not found error). Please fix your code.
Others:
https://www.lebara.co.uk//en/accessibility.html
https://www.lebara.co.uk//en/lebara-tax-strategy.html
https://www.lebara.co.uk//en/privacy-notice.html
https://www.lebara.co.uk//en/cookies-notice.html