Adding / removing 2nd+ vocabulary to a workspace shows error

1) Create a new workspace 2) Add a vocabulary to the workspace - it is OK 3) Add another vocabulary to the workspace - an error is shown

However, the 2nd vocabulary was actually added - I can see it in the workspace after refresh (F5).

Console:

AjaxObservable.ts:272 POST https://xn--slovnk-7va.gov.cz/modelujeme/sluzby/sgov-server/workspaces/instance-1584195892/vocabularies?vocabularyUri=https://slovn%C3%ADk.gov.cz/generick%C3%BD/osoby&readOnly=false&label=undefined 409
t.send @ AjaxObservable.ts:272
t @ AjaxObservable.ts:221
t._subscribe @ AjaxObservable.ts:139
e._trySubscribe @ Observable.ts:239
e.subscribe @ Observable.ts:221
e.call @ tap.ts:82
e.subscribe @ Observable.ts:215
e.call @ mapTo.ts:52
e.subscribe @ Observable.ts:215
e.call @ catchError.ts:106
e.subscribe @ Observable.ts:215
(anonymous) @ ImportVocabularyForm.tsx:136
onClick @ ImportVocabularyForm.tsx:257
Be @ react-dom.production.min.js:54
ze @ react-dom.production.min.js:54
(anonymous) @ react-dom.production.min.js:55
Mr @ react-dom.production.min.js:105
Dr @ react-dom.production.min.js:106
(anonymous) @ react-dom.production.min.js:117
Wu @ react-dom.production.min.js:272
Le @ react-dom.production.min.js:52
qr @ react-dom.production.min.js:109
Qt @ react-dom.production.min.js:74
Yt @ react-dom.production.min.js:73
hostReportError.ts:8 Uncaught e {message: 'ajax error 409', name: 'AjaxError', xhr: XMLHttpRequest, request: {…}, status: 409, …}
(anonymous) @ hostReportError.ts:8
setTimeout (async)
r @ hostReportError.ts:8
t.error @ Subscriber.ts:238
t._error @ Subscriber.ts:144
t.error @ Subscriber.ts:114
t.notifyError @ innerSubscribe.ts:71
t._error @ innerSubscribe.ts:35
t.error @ Subscriber.ts:114
(anonymous) @ throwError.ts:72
e._trySubscribe @ Observable.ts:239
e.subscribe @ Observable.ts:221
c @ innerSubscribe.ts:112
t.error @ catchError.ts:142
t._error @ Subscriber.ts:144
t.error @ Subscriber.ts:114
t._error @ tap.ts:136
t.error @ Subscriber.ts:114
t._error @ Subscriber.ts:144
t.error @ Subscriber.ts:114
u @ AjaxObservable.ts:416
load (async)
t.setupEvents @ AjaxObservable.ts:420
t.send @ AjaxObservable.ts:249
t @ AjaxObservable.ts:221
t._subscribe @ AjaxObservable.ts:139
e._trySubscribe @ Observable.ts:239
e.subscribe @ Observable.ts:221
e.call @ tap.ts:82
e.subscribe @ Observable.ts:215
e.call @ mapTo.ts:52
e.subscribe @ Observable.ts:215
e.call @ catchError.ts:106
e.subscribe @ Observable.ts:215
(anonymous) @ ImportVocabularyForm.tsx:136
onClick @ ImportVocabularyForm.tsx:257
Be @ react-dom.production.min.js:54
ze @ react-dom.production.min.js:54
(anonymous) @ react-dom.production.min.js:55
Mr @ react-dom.production.min.js:105
Dr @ react-dom.production.min.js:106
(anonymous) @ react-dom.production.min.js:117
Wu @ react-dom.production.min.js:272
Le @ react-dom.production.min.js:52
qr @ react-dom.production.min.js:109
Qt @ react-dom.production.min.js:74
Yt @ react-dom.production.min.js:73

Similar situation occurs when I remove a vocabulary from a workspace after I removed another one.

datagov-cz / sgov-assembly-line

Adding / removing 2nd+ vocabulary to a workspace shows error #84