I’ve seen there are a few other issues related to this and sent support a message a few days ago but haven’t heard anything back yet, so trying my luck here:
SSL works well with render URL:
https://wtw-frontend.onrender.com/
But it doesn’t work (not secure) with my custom domain.
Already tried to delete and re-add, no luck.
Domain is registered with Google Domains, there is no ALIAS so I set an A record pointing to the given IP
Any help? 
Hi @chrisid, I’ll be happy to help with this. Sorry we missed your earlier support message. Where did you submit it?
Hi David, thanks a lot for that!
Sent an email to support@render.com 7th Feb.
It should be working now! Let me know if you continue to see any issues. We had to update a DNS record so the fix may take a short amount of time to propagate.
I’ll investigate why we didn’t respond to your initial email. We normally reply within 1 business day.
It’s all good indeed.
Thank you very much @david , have a great evening!
It’s my pleasure @chrisid.
I found your original email in the spam folder. Sorry about that. I created a filter to prevent this from happening again if you email us in the future.