I'm Kenneth one of the co-founders here at Seedly.
We actually wrote a detailed piece about this here: https://blog.seedly.sg/seedly-security/
Essentially, We have met with representatives of DBS last week to discuss this issue, and both organisations are fully aligned that online security is of utmost importance to all of our users.
Please do read the blog piece and let me know if you have any questions. Cheers!
Both DBS and SC has issue with their links on the bank side (not seedly side). Maybe you can contact seedly help directly within the app to find out more.