SAP estimates a patch release for BI 4.3 SP01 May 21 2021. Patches for BI 4.2 SP08 and SP09 are estimated May/June timeframe.
SAP has released patches for BI 4.3 and BI 4.2 that address this issue. SAP Note 3012378 below and attached.
3012378 - File not uploaded to Folder using Restful Webservice SDK - SAP ONE Support Launchpad
Using BI 4.3 SP01 or BI 4.2 SP08 FP5 or later, delivery to either SAP BusinessObjects Folder or SAP BusinessObjects Inbox succeeds from InfoBurst but the files do not appear in BusinessObjects. This is a software fault and is being investigated by SAP.