USERSTORE_TOKENPERM growing very fast I'm experiencing a very weird problem with userstore_tokenperm clerk recently.

We have an environment with some databases in contained mode executing in version SQL Server 2017. Anyway i'm facing this problem since the SQL Server 2016.

At a certain moment this cache starts to grow at a rate of 6GB by day. When this ocurr we have to do a failover and restart the principal node of AG.

Run DBCC FREESYSTEMCACHE ('TokenAndPermUserStore') does not clear the cache. We are considering to use the trace flags 4621 as suggested by microsoft to avoid this memory pressure, but i want to know if someone has a tip to help me  to understand this behavior. This seems like a memory leak, because even running DBCC FREESYSTEMCACHE the objects are not released from memory.

We have around to 70 users in contained mode in this server and when the cache starts to grow it grow until starve the server for memory.

I tried to find out what kind of class of token is present and the worse instance have only this entrys.

In sys.dm_os_memory_clerks we already faced more than 30GB of consumption

Someone please can help with some troubleshooting hint or even with an experience about this kind of problem.

Thks in advance
Edit: sorry for not returning with a solution for this case.
The MS support suggested me change the language of user from us_english to NONE. The last response from the support was ... "Probably a memory leak when the user store token, which is 8 kb, needs to be created to store a certain word due to the default language setting. To have more details and confirm what word is causing this high memory usage, these other collections would be necessary. "
As I had no problem after the adjustment, it was not possible to capture any new dump and therefore the solution may have occurred due to another scenario including the applications that are used on this server. Thanks Brent Ozar by the hint