Audio have wired glitch

[omar5DC2]

please, what is wrong  and how to fix this, it will fix itself if i open another program than go bakc to Pr however there will be more bugs in different parts of the audio,, I'm using Pr 2020 like i did for 2 years and this is the first time i get this bug , its not the Ram and I've cleard the cache but still and I'm sure the audio clip is fine,,,, thank you 

[John V Knowles]

Is this "knock" sound in the captured audio of your source clips, or only in export?

[omar5DC2]

No, it just on the export

[John V Knowles]

Do you have filters or effects applied to your audio?

What are your export settings?