From https://www.pcmag.com/how-to/record-calls-on-your-android-phone :

Recording Limitations on Android

Google has never been particularly fond of call-recording apps for Android, at least not those from third parties. With Android 9, the company added limitations that prevented many apps from recording your phone conversations. The apps continued to work, but when you played the recording, you could only hear your end of the conversation—or complete silence.

Android 10 cracked down even further on these types of apps by blocking call recording via the microphone. In response, many app developers started tapping into Android’s Accessibility Service to record phone calls. But Google then updated its developer policy in April 2022 to state that it would not allow apps in the Play Store to use the accessibility service for call recording. That policy went into effect on May 11, 2022.

The company has even gone so far as to label call recording a type of spyware. “Behaviors that can be considered as spying on the user can also be flagged as spyware,” Google said in its developer policy. “For example, recording audio or recording calls made to the phone, or stealing app data.”

In the past, people were able to find workarounds to Google's block, such as changing the audio source or format, turning the speaker volume as loud as possible, recording manually instead of automatically, and even rooting their phones. Others have since taken to sideloading call-recording apps through an APK file rather than downloading them directly from Google Play.

The version of Android installed on your phone also plays a role in all this. Apps on devices with Android 9 and earlier should still be able to record phone calls without bumping into Google’s latest restrictions. But apps on phones with Android 10 or higher that try to use the accessibility service may run afoul of Google’s new policy.

I've looked through the F-Droid repository for a call-recording app before, but didn't find one that worked. It's been a while, so maybe I ought to try again. Otherwise, I'm open to suggestions!