Working Remotely in UK as Non Tax Resident

Hi - i am a UK citizen but non UK (tax) resident employed full time (35+ hours) in the Netherlands. My firm in the Netherlands allows me to work 20 days remotely each year for which i plan to work in the UK. When i left the UK i completed a P85 form, to confirm my understanding is correct i'm not liable to any UK tax on these remote working days as i'm a non resident and i'm working for my NL firm (and will be paid by them) for less than 30 days a year? To quote 'If you work full-time abroad, you can usually visit the UK for up to 90 days - as long as you work no more than 30 of these days.' https://www.gov.uk/tax-right-retire-abroad-return-to-uk

Hi,
Yes, that is correct.
Thank you.