nope. Didn't visit those countries. But my experience with SIMBA roaming is seamless. Though simba said it's roaming ready, at the end point, it's down to the phone and it's settings. I'm using Galaxy S21+ on eSIM. APN set to TPG, data roaming on, network selection automatic.
Should anyone encounter issues with no network, do restart your phone, it's is always advised even if you buy ICC roaming cards. Make sure the SIMBA sim is set as default. Some people have dual-sim in their phones, they have to make SIMBA the primary, and set data usage as SIMBA. Also if one have dual-sim, make SIMBA Sim in the SIM 1 slot. This is what I learn from using ICC card, make the roaming card as SIM 1, your local other SIM as SIM 2.
Next if can't using automatic, switch to manual and manually select the network listed on SIMBA website. If it's still can't then it's the roaming partner issue. Can't really blame SIMBA. When people go overseas, whether you can roam or not, it's dependant on roaming partner. It's stated on telco website, that's for M1, Starhub Singtel too.
Though data roaming is set on, android phones might restrict it due to data limit reached. I've seen people don't have data is because their data limit reached and data automatically turned off.