No, it’s not a bug.

QB calculates pay in hours and minutes, to the closest second.

28:05 is the same as  28.08333333333330

28.08333333333330 * 18 = 505.500000000…  (exactly 505.50)

At the same time:

28.08 * 18 = 505.440000000…  (exactly 505.44)

To get that result you have to enter 28.08 while the time preference is set to […]

Resolution for 'closest second issue: 'Wages calculating 6 cents over each pay. Time of 28:05 (28 hrs/ 5 min) converts to decimal 28.08 x $18.00 = $505.44, QB shows as $505.50 Is this a bug with a fix?' available: Yes.

The closest second issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the closest second issue yourself by looking for a resolution described in the article. If it is a complex closest second issue or you are unable to solve the issue, you may contact us by clicking here or by using other closest second support options.

For more information about resolving issues related to closest second in Quickbooks/QBO or to get support for the issue 'Wages calculating 6 cents over each pay. Time of 28:05 (28 hrs/ 5 min) converts to decimal 28.08 x $18.00 = $505.44, QB shows as $505.50 Is this a bug with a fix?', click the link below: