All history version turn to blank

[jiangxiaoqiang]

Today one of my yjs document turn to blank for all versions, this is the version info that store in PostgreSQL:

src/sql/version.sql

and this is the table ddl:

-- public.tex_sync_history definition

-- Drop table

-- DROP TABLE public.tex_sync_history;

CREATE TABLE public.tex_sync_history (
	id int8 GENERATED ALWAYS AS IDENTITY( INCREMENT BY 1 MINVALUE 1 MAXVALUE 9223372036854775807 START 1 CACHE 1 NO CYCLE) NOT NULL,
	"key" varchar NOT NULL,
	value bytea NOT NULL,
	"version" varchar NOT NULL,
	content_type varchar NOT NULL,
	doc_name varchar NOT NULL,
	clock int4 NOT NULL,
	"source" varchar NOT NULL,
	created_time timestamp DEFAULT CURRENT_TIMESTAMP NOT NULL,
	project_id varchar NOT NULL,
	CONSTRAINT tex_sync_history_unique UNIQUE (key)
);

this is how I apply the history version info:

async getYDoc(docName: string): Promise<Y.Doc> {
    const updates: Array<TeXSync> = await this.getPgBulkData(
      this.pool,
      { values: true, keys: false, reverse: false },
      docName
    );
    const ydoc = new Y.Doc();
    ydoc.transact(() => {
      try {
        for (let i = 0; i < updates.length; i++) {
          let update: TeXSync = updates[i];
          let updateVal: Uint8Array = update.value;
          Y.applyUpdate(ydoc, updateVal);
          let txt = ydoc.getText(docName);
          let txt1 = txt.toString();
          console.log(txt1);
        }
      } catch (err) {
        console.error("apply update failed", err);
      }
    });
    return ydoc;
  }
}

all the version from start to end get ‘’ . why did this happen? what should I do to fixed this issue? This is the minimal example:

src/getydoc.ts

it look like the same with The document becomes blank when the DB is under high load and communication fails during connection