Perhaps you caught wind of LinkedIn changing your messaging tab this week.
Today LinkedIn confirmed the roll-out of a new 'Focused Inbox' format for all app users, routing fewer-value messages to an "Other" tab on your LinkedIn message stream.

Launched first last September, Focused Inbox gives you two different tabs for InMail: 'Focused' and 'Other'. Here, 'Other' could be just as accurately dubbed 'Spam' - the point is, however, to cut through the spam and surface the most relevant outreach in the app.
Here's LinkedIn Product Manager Deepan Mehta on explaining:

"We heard from many of you that you wanted a better way to organize your LinkedIn inbox, so I am excited today to share that we are rolling out a new and improved LinkedIn messaging experience that should make it easier for members around the globe to find and respond to the messages that matter most.". Focused Inbox gives users a two-poled experience, separating all the incoming messages into "Focused" and "Other." Focused has the most relevant new opportunities and outreach, while Other contains all other conversations."
Mehta further says that 'conversations' on LinkedIn are up almost 20% year over year, and people are increasingly using messaging to connect with and engage with one another in the app.

'Conversations' is a bit of a vague term, but LinkedIn doesn't tend to get much more specific with engagement numbers either. To give you some context, LinkedIn says that it has experienced "record levels" of engagement each quarter since 2018 when Microsoft bought the professional networking app.
 
Microsoft invented the Focused Inbox principle. It was originally deployed in Outlook before making the leap over to LinkedIn.

How much that improves the experience will largely depend on how many messages you get – though it's interesting to see where paid InMails from LinkedIn wind up.

You'd think, at least, that LinkedIn would still be pushing its paid promos into your main inbox, though a promotion from LinkedIn got filtered into my 'Other' folder this week. Just one thing to keep in mind.

According to Mehta, LinkedIn is gradually unrolling Focused Inbox to all users around the world, meaning if you haven't received one yet, you will likely soon.