There could be several reasons for the instability of your OpenVPN connection. Here are a few suggestions to try and improve its stability:

1. Check server resources: Ensure that the VPS has sufficient resources, such as CPU, memory, and bandwidth, to handle the VPN traffic along with the small business card site. DigitalOcean offers different plans, so you might consider upgrading to a higher-tier plan if necessary.

2. Optimize VPN configuration: Review the OpenVPN configuration file and ensure that it is properly optimized for your specific use case. You may find guidance on OpenVPN's dоcumentation or online forums to optimize the configuration based on your requirements.

3. Test different VPN protocols: OpenVPN supports various protocols, such as UDP and TCP. Try switching between them to see if one provides better stability. Sometimes, certain networks can cause issues with specific protocols, so experimenting with different options might help.

4. Modify firewall settings: Ensure that the VPS firewall is not overly restrictive and is allowing the necessary traffic for the VPN connection. Check if any firewall rules or security groups are interfering with the VPN traffic and adjust them accordingly.

5. Monitor network connectivity: Keep an eye on the network connectivity between your VPS and the clients. Tools like ping or traceroute can help identify any network connectivity issues. This information can be useful when troubleshooting or contacting the VPS provider's support team.

6. Contact DigitalOcean support: If the issue persists, it may be worth reaching out to DigitalOcean support for assistance. They can investigate further and provide recommendations specific to your setup.