Looking at the certs presented by the server:

 ✘ basti@basti-nuc  /etc/pki/ca-trust/extracted/java  openssl s_client -connect jabber.space.net:5223
CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G2
verify return:1
depth=1 C = US, O = DigiCert Inc, OU = www.digi cert.com, CN = RapidSSL TLS RSA CA G1
verify return:1
depth=0 CN = *.space.net
verify return:1
---
Certificate chain
 0 s:CN = *.space.net
   i:C = US, O = DigiCert Inc, OU = www.digicert.com, CN = RapidSSL TLS RSA CA G1
   a:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA256
   v:NotBefore: May  2 00:00:00 2022 GMT; NotAfter: May 16 23:59:59 2023 GMT
 1 s:C = US, O = DigiCert Inc, OU = www.digicert.com, CN = RapidSSL TLS RSA CA G1
   i:C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G2
   a:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA256
   v:NotBefore: Nov  2 12:24:33 2017 GMT; NotAfter: Nov  2 12:24:33 2027 GMT
---

Looking at they keystore for the Certs shows that it's there:
 basti@basti-nuc  /etc/pki/ca-trust/extracted/java  /usr/lib/jvm/java-17-openjdk-17.0.3.0.7-1.fc36.x86_64/bin/keytool -list -cacerts -alias digicertglobalrootg2 -v
Keystore-Kennwort eingeben:


Aliasname: digicertglobalrootg2
Erstellungsdatum: 10.05.2022
Eintragstyp: trustedCertEntry

Eigentümer: CN=DigiCert Global Root G2, OU=www.digicert.com, O=DigiCert Inc, C=US
Aussteller: CN=DigiCert Global Root G2, OU=www.digicert.com, O=DigiCert Inc, C=US
Seriennummer: 33af1e6a711a9a0bb2864b11d09fae5
Gültig von: Thu Aug 01 14:00:00 CEST 2013 bis: Fri Jan 15 13:00:00 CET 2038
Zertifikatsfingerprints:
	 SHA1: DF:3C:24:F9:BF:D6:66:76:1B:26:80:73:FE:06:D1:CC:8D:4F:82:A4
	 SHA256: CB:3C:CB:B7:60:31:E5:E0:13:8F:8D:D3:9A:23:F9:DE:47:FF:C3:5E:43:C1:14:4C:EA:27:D4:6A:5A:B1:CB:5F
Signaturalgorithmusname: SHA256withRSA
Public Key-Algorithmus von Subject: 2048-Bit-RSA-Schlüssel
Version: 3

Erweiterungen:

#1: ObjectId: 2.5.29.19 Criticality=true
BasicConstraints:[
  CA:true
  PathLen: no limit
]

#2: ObjectId: 2.5.29.15 Criticality=true
KeyUsage [
  DigitalSignature
  Key_CertSign
  Crl_Sign
]

#3: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: 4E 22 54 20 18 95 E6 E3   6E E6 0F FA FA B9 12 ED  N"T ....n.......
0010: 06 17 8F 39                                        ...9
]
]