I am having an issue with sharepoint web services

[krdube]

Hi we are running a sharepoint 2016 on premise server. When opening files through a client application (called Bluebeam, an alternative PDF editor to adobe) it is calling the following web services for every content type in the library (i'm getting this from fiddler)

POST /lrc/LandUse/_vti_bin/Lists.asmx HTTP/1.1

SOAPAction: "http://schemas.microsoft.com/sharepoint/soap/GetListContentType"

in my farm when it tries to open a file it has to make this call for every content type in the library.  the first time i open the file it takes about 15-20 seconds for each of these calls to complete and there about about 10 content types in the library so it takes a Long time to open the document.  Weirdly this doesn't happen in all my libraries, only in some, i think its happening in some libraries that were created from templates originally. Note that when it does happen it only happens the first time a document is loaded from the library, on subsequent times it is ok.  Has anyone seen this and might know what is causing this weird issue?

[#2]

@krdube 2 issues here-

1) The calls taking 15-20 seconds might point to performance issues with the server

2) BlueBeam could use other calls that are not relying on legacy APIs (ASMX web services) to get that data, possibly in one call. They could also use async calls to that you don't end up multiplying the amount of time taken by the calls since they can all be executed in approximately the same time frame. I believe they could get the info with the REST endpoint. Make sure you are using a version of their product that is compatible with SP 2016 on-prem.

[#3]

@WestleyH   thanks for the suggestions... i'm chasing this down with premier support.  just to update as to where I am with this now... it appears that the web service calls are actually fast, its just that the application takes a long time between calls, i'm thinking its loading all the managed metadata termsets into memory or ??.   

The weird part about this issue is that as soon as i make one of my content types the default content type for a library, this is when the application (bluebeam) starts loading all the content types (regardless of what content type the document is).  This isn't happening in all of my site collections, only some of them.  I'm not sure what is making it load the content types in the affected site collections.  I can confirm its using the Lists.asmx web service calling "GetListContentType".  After it does this call it takes 23 seconds until it calls it again for the next content type.  At first i thought the call took that long but with support they pointed out the call is less than a second, its the application thats taking 23 seconds.  But why its calling it is a mystery.. it does it in some site collections but not others...

[#4]

It seems like it may just be an issue with the logic in the 3rd party application. We would need to debug that to see why it is taking so long, and how they decide to pull content types etc.

[#5]

ya, the strange part is that this is confined to document libraries created in a a particular spweb. If i go to subsites under this web they are ok, its only happening in one particular web. Or if i go to other site collections its ok.  Really strange...  The web that its happening is a root web under the site collection...