MB Still Permanently Adjusting the Volume when Converting from Opus

[AsaNo88]

Hi, everyone!
I just started using MB this past couple of weeks. I might have found a bug (or two?) related to Opus in MB but chose to ask this first, because I might've missed out on something obvious. I've read FAQs, MB's wiki pages, and search through the forum, but I didn't find anything similar.

When I convert from an Opus file, it seems that MB persists on permanently adjusting the volume whether or not the corresponding checkbox being ticked or unticked. This is so far the conclusion I've reached after my 3rd attempt converting the file. I've made sure the replay gain under controls menu was off before playing the file, yet the converted file's volume was clearly much lower than the the source file.

First attempt, I tried ticking the checkbox then convert, then unticking the checkbox again for another convert to make sure it's not just a graphical bug. But, the two results are exactly the same.

Then for second attempt. I tried clearing the replay gain tags from within MB using "Restore Original Volume". I checked the file in tag editor and tag inspector first and no replay gain tags at all as expected.

       

But even after that somehow MB was still permanently adjusting the volume when converting. The volume was still as low as the first attempt.

Third attempt, I tried inspecting the file with Foobar2k. Apparently, the same file that I've restored to original volume on MB still had a replay gain tag as seen below.

Is this an intended behavior? This is the second thing that I thought might also be another bug.
I removed all replay gain information with Foobar2k, then made sure to rescan the file in MB. After converting for the third attempt, the converted file is finally as loud as the original.

I was converting from Opus to AAC (my music player doesn't support Opus) with this parameters for all attempts:
--tvbr 82 --ignorelength -o [outputfile] -
I can provide both the original and the converted files in each of the 3 attempts above (so 6 files in total) if it might help for these 2 issues, but I don't know whether or not sharing a whole song is something that is frowned upon here. I didn't find any guideline page in this forum. I've also tried converting from Opus to MP3 but the same thing still happened. And none of the 2 issues above happened when I used MP3 or M4A file as the source. The convert results are as loud as the originals and no replay gain tag left after restoring to the original volume. Seems like it only happens with Opus file.

Thank you in advance for any kind of help.

[AsaNo88]

I finally got some time to read more about this. It's very likely that this is the same thing that happened to me here https://getmusicbee.com/forum/index.php?topic=34965.0
Apparently it's caused by MusicBee applying, by default, Opus header output gain when encoding. Is this count as a bug? If so I will come back to post it in the bug report. So far there's no option to turn it off or even knowing about it in MusicBee itself. I ended up rescanning all my Opus files and clearing all of their header gain using fb2k. At least I also learned a lot about replaygain and how MB and fb2k handles this header output gain. It seems that Opus people want to do replaygain by their own rule, but I found a lot of it is really restricting and confusing.