Fast catchup stuck at processing accounts for TestNet

Hello! I’m new to Algorand and I’m trying to follow the Getting Started with Python SDK tutorial. When I run sudo ./sandbox up testnet, I get:

Starting sandbox for: testnet
see sandbox.log for detailed progress, or use -v.
* docker containers started!
* waiting for services to initialize.
* services ready!

algod version
3.12.2.stable [rel/stable] (commit #181490e3)
go-algorand is licensed with AGPLv3.0
source code available at

Indexer version
Indexer disabled for this configuration.

Postgres version
postgres (PostgreSQL) 13.9

algod - goal node status
Last committed block: 0
Time since last block: 0.0s
Sync Time: 0.0s
Last consensus protocol:
Next consensus protocol:
Round for next consensus protocol: 1
Next consensus protocol supported: true
Last Catchpoint: 
Genesis ID: testnet-v1.0
Genesis hash: SGO1GKSzyE7IEPItTxCByw9x8FmnrCDexi9/cOUJOiI=

indexer - health
Indexer disabled for this configuration.

Starting fast-catchup with catchpoint: 25970000#OQTWEQITJHVWJ5OI7LWTXYF5243TXJQWQ3NETVMGKYATVQJUNELQ
Processing accounts: : [                                        ] [0/1000] 0%

And it gets stuck there. I saw this post which seemed to be having the same problem, but the suggested solution did not work for me. I’m working on Ubuntu 22.04, with this SSD and 8GB of RAM.

Does anybody know what could be wrong?
Thank you in advance!