Broadlands, was your UK-issued EASA Part-FCL licence received by Malta before 31 Dec 2020? If so, then anything valid at the time should have been transferred to your Malta-issued licence.
I took a similar case up at EASA a year or so ago, when the IAA hadn't issued FE certificates to pilots who had SOLI'd from the UK. The EASA rulemakers confirmed that this was incorrect under EU law - the 'new' state had no powers to revoke privileges included in the licence issued by the 'old' state.