Editing a video brochure

I am relatively new to Premiere Pro and have been asked by a client to edit a video brochure.

When exporting, everything looks fine, but once I deliver to the business and they upload the video, there is a loss of quality. Particularly in a few points, I have uploaded screenshots for reference.

As you will see, the text looks blurry. Also, some of the footage lags.

I have also attached the spec for the video and my sequence and export settings. Where am I going wrong?

Thank you in advance for your help on this.