When any editing is done in the online version, this is a problem that has been reported for a long time.
Can you isolate whether it is also a problem when all work is done in the desktop applications?
Note: this is not the place to get any changes made in Word nor the attention of developers at Microsoft. This is an independent user-to-user support forum. MS does not see anything you post here. The way to get their attention is through the feedback mechanisms.
• How do I give feedback on Microsoft Office? https://support.microsoft.com/office/2b102d44-b43f-4dd2-9ff4-23cf144cfb11
• Send Feedback to MS Developers https://answers.microsoft.com/en-us/msoffice/forum/all/microsoft-feedback-process/6f850368-8c86-481d-a207-d95b265c4be4
• Bonus Reading related to MS Feedback system https://answers.microsoft.com/en-us/windows/forum/windows_10-windows_install/bonus-reading-related-to-ms-feedback-system/506e7654-8ced-405b-911e-c58d8f253069
While MS is aware of the problem and working on a fix, more feedback will help by giving them more data as well as keeping the pressure on.