Button Design Issues When Sending Stripo Templates via Outlook

Hello,
I am a Stripo user and I'm reaching out regarding design rendering issues I've been experiencing with email buttons.
I create email designs in Stripo, export them as HTML, and send them through our company email system (Outlook). I paste the HTML code into Outlook's message body and convert it before sending.

*Issue Description:
While the emails display correctly when viewed in Outlook, I'm encountering the following problems when recipients open them in Gmail or other email clients:

The text above the buttons appears broken/distorted
Vertical bar-like shapes appear on the button borders (see attached image)
Oval/rounded buttons fail to render properly and don't display their intended shape at all.

*Current Workflow: Design in Stripo → Export as HTML → Paste into Outlook → Convert HTML → Send

Could you please advise on how to resolve these rendering issues? I suspect this may be related to how the HTML is being processed through Outlook, but I wanted to check if there are any best practices or workarounds you'd recommend.

Thank you for your assistance.

Best regards,
HW