site link changes when emailed

4 days ago, links emailed to either me or my web directory users changed to a different website
I can check email logs and the URL is correct, however when received to an inbox of mine or customer, the link has changed to another domain of mine but with a very long and non working link

Example – This was sent out – SITE: https://mdjn.uk
PLUGIN VERSION: 7.9.2
WORDPRESS VERSION: 6.1.1

However this is what was received – SITE: http://url9074.mobiledjnetwork.co.uk/ls/click?upn=HrbDw9jzJmm5qnvHQThri6jkj22AjQeGi3L-2FTFkXfic-3Di97m_0cIsmrEkybRE0w2K-2F9QP0N9lEwtlSy1gP24G0cWKyKnptWpcWbubemQ1EEBKaCM-2F69ibNXeX8XLz5JffzX-2BfkjxUC-2BWGwTVPy3dr6m-2FkM8ls3z3Hw9Uhh8xcRUOgi7ijPi09a2IuRHt-2FaWqekdpbzzPKHhlZwfFBKk5LQ44TUzxcDBXWhgRq1eOmFPQCaWBbWedNI81jDW-2BedFjXIqBXJw-3D-3D
PLUGIN VERSION: 7.9.2
WORDPRESS VERSION: 6.1.1

Any idea what is messing with this link (site is changed in ALL outbound emails with links)?

Thanks!