Hi mate
With Halifax I`ve never had any problem, I set up my Thai Kasikorn bank account as a payee whilst still in the UK, no problems with transfers.
I did however inform them quite some time ago that I would be spending a lot of time in Thailand.
With Santander, it appears they are able to detect different ISPs, has caused occasional problem,sometimes have to go through extra security.
I`d
with Fork, let them know and maybe bring your UK phone ( or SIM) with you in case they need to contact you ?