Some posts have stated that ‘the rules changed last year’ (but don't say what rules they are referring to) and that an IDP can only be used by temporary visitors to Malaysia.
The Road Transport Act 1987 (which sets out the rules for driving in Malaysia) is still in force, and has recently been amended to bring in stricter penalties regarding dangerous driving and drink driving, but there don't seem to be any other changes. There is more detail on the Road Transport Act 1987 here: https://www.lawyerment.com/library/legislation/acts/1987/333/
I decided to email JPJ to check and I received an email response from them on 30 October 2020 confirming I “can use UK Valid Domestic Driving License and International Driving Permit (IDP) (According to the defined format on the Convention on Road Traffic Geneva 1949) to drive in Malaysia.”
The UK government FCO website says the following, which seems to indicate that an IDP can be used for longer term visitors (but a new one needs to be purchased each year). However, also note that if you are not UK resident you cannot legally renew your UK driving licence Photocard when it expires!
However, getting an IDP from your home country can be inconvenient so you may decide to take the JPJ driving test to obtain a Malaysian driving licence. This will remove any doubt over the validity of your driving licence. I took my test in March 2020. See my post here: https://spousevisamalaysia.blogspot.com/2020/03/malaysian-driving-lessons-test-for.html
