Your subscription tier is only one part of the story. Yes, the Clipchamp free export resolution limit caps output at Full HD, but if your video looks softer than expected even at 1080p, several other culprits are usually at play. Working through them one by one will save you from assuming an upgrade is the only fix.
Start with your source footage. Clipchamp exports at the quality of what you put on the timeline, and it won't upscale. GoPro and phone recordings often use the HEVC/H.265 codec, which can cause compatibility issues, along with high-resolution formats that are too large for Clipchamp to handle smoothly. Converting clips to H.264 MP4 before importing keeps detail intact.
System resources matter just as much. High-resolution exports require more resources, so if 1080p stalls, dropping to 720p, checking storage space, and closing other heavy programs can help. In the browser, avoid surfing in other tabs while exporting, since your browser can de-prioritize the process and cause it to slow down or stop. A stale cache or outdated Chrome or Edge is another common cause.
Sometimes the problem shows up as a missing picture or sound rather than a resolution drop. Audio tracks may not stay aligned after splitting a clip, and re-importing the audio and confirming its position on the timeline usually resolves it.
Finally, try disabling hardware acceleration in the export settings, which frequently clears stubborn failures at the cost of a slower render.