The iCloud features are partially not working

I reinstalled macOS on my macbook (currently running 10.15.7) and some of the iCloud features stopped working for me. Syncing tabs and history in Safari doesn't work and also Personal Hotspot on iPhone doesn't show up in the wifi menu on my mac (but works if activated manually).

Also login to iCloud is painfully slow, asking for my mac or iPhone password several times (as I understand to decrypt data). And such a long login came after I updated my iPhone to iOS 15. Then I rolled back to iOS 14 while it was still possible and had the same problem of long login time, but all functions continue to work on IPhone.

I've tried both logging out of Icloud on all devices, reinstalling the system again, and booting with a new user account. The problem remains.

Also cloudd and SafariBookmarksSyncAgent throw those errors to the Console:

cloudd: Couldn't preflight PCS identities for the current service. Failing zone fetches for operation <private>

cloudd: nw_parameters_set_source_application_by_bundle_id_internal Failed to convert from bundle ID (com.apple.SafariBookmarksSyncAgent) to UUID. This could lead to wrong data usage accounting.

cloudd: nw_endpoint_flow_validate_delegation [C392.1 IPv4#44dcd954:443 in_progress socket-flow (satisfied (Path is satisfied), interface: utun0, ipv4, ipv6, dns)] Network Delegation Failure: Invalid Bundle ID "com.apple.SafariBookmarksSyncAgent" [M]

SafariBookmarksSyncAgent: Failed to save record due to unrecoverable error: Error Domain=CKErrorDomain Code=110 "Request UUID: (null)"

SafariBookmarksSyncAgent: Did fail to save iCloud Tab record batch with error: Error Domain=CKErrorDomain Code=2 "Request UUID: (null); Partial errors: RecordID: <CKRecordID: 0x7f979841a130; recordName=E0E81A2C-9F89-46E1-AB62-1C2F697DEEAF, zoneID=CloudTabs:__defaultOwner__>, Error: Error Domain=CKErrorDomain Code=110 "(null)"; RecordID: <CKRecordID: 0x7f9798446790; recordName=61CC449C-225A-4FA7-B7AF-847EA6E9D553, zoneID=CloudTabs:__defaultOwner__>, Error: Error Domain=CKErrorDomain Code=110 "(null)"; RecordID: <CKRecordID: 0x7f9798449b50; recordName=89A7CF12-C73E-4A6A-B3F6-46AF4A761FD9, zoneID=CloudTabs:__defaultOwner__>, Error: Error Domain=CKErrorDomain Code=110 "(null)"; RecordID: <CKRecordID: 0x7f97984132a0; recordName=7688E349-B2E0-46ED-B670-1FD675995DFE, zoneID=CloudTabs:__defaultOwner__>, Error: Error Domain=CKErrorDomain Code=110 "(null)"; RecordID: <CKRecordID: 0x7f97984470b0; recordName=F42683A7-17BB-4374-8500-9CC104442274, zoneID=CloudTabs:__defaultOwner__>, Error: Error Domain=CKErrorDomain Code=110 "(null)"; RecordID: <CKRecordID: 0x7f97984470f0; recordName=FB300D5<…>